Hot on the heels of last week's #TuesdayTip about writing realistic relationships, I am staying with that broad theme and this time want to examine realism in general.
I write police procedurals grounded largely in reality. I am not a police officer, and have no experience in law enforcement, but I try to be as procedurally accurate as possible, whilst acknowledging that compromises need to be made in order to serve up a dramatic story (see #TuesdayTip49 for more on this).
I also like to get as many verifiable details about other, non-procedural things as correct as possible. I will never forget one of my proof-readers early comments for my first novel, The Last Straw. The book is set in the summer of 2011, but as is the way with these things, it was well into 2013 by the time it was submitted and edited. In one throw-away comment, I mentioned how the dry weather had affected Warren's lawn. My proof-reader's comment was succinct: 'I looked it up and the summer of 2011 was actually quite wet in Hertfordshire'. A later comment on the same manuscript noted that the radio station that Warren was listening to in the car had changed its name the year before.


A couple of years later, I received not one but TWO comments in my Amazon reviews for Silent As The Grave (both from Americans, bizarrely) pointing out that a hospital in Coventry, UK, wasn't built until a couple of years after I had a character being born there.
Since then, I have been a stickler for trying to get as many of the small details correct. Not only is it a way to avoid those negative reviews and save my proof-reader some time, it also provides a brilliant excuse for procrastination!


Promoting Pedantry
My books always have a date (although I tend not to specify the year), so here are some of the things I do.

• Susan, Warren's wife, is a teacher, so I look up the term dates for Hertfordshire schools, to work out if she is likely to be off school during the period it is set in.
• I check for public holidays (remember, Easter etc can move around).
• I look up sunrise and sunset times - if my killer is disposing of the body after dark, then they won't be doing it at 7pm in June!
• I check when the clocks change. It hasn't caused me problems yet, but you can guarantee that the one time I don't check will be the book which requires a precise timeline that straddles early evening on one day, finishing in the early hours of the following day, and I set the scene over the weekend when the clocks go back.
• The BBC and Sky etc archive their TV listings, so I can have a character give an accurate alibi or have Warren settle down to Have I Got News For You, confident that it was showing that evening (for bonus points, I can even reference the guests, knowing that somewhere out there I have just thwarted a pedant!).
• Similarly, football fixtures are archived (with kick off, score etc) - useful if a character claims to have been watching the footie.
• When describing cars, I double-check that the model of car was available in the UK for the registration date I give. Wikipedia and online car magazines can provide photographs to help in its description. For one book, I changed the timeline to ensure that a car with a particular feature was on sale during that time period.
• The BBC News website has archived its content, making it easy to find out what the major news stories were that day. No matter how horribly gruesome my murder is, it isn't going to have made the top story on the day of the EU referendum! Even if it has no impact on the plot, it adds a little colour and texture to the story.

Where to find that information
Googling for these little details is an obvious solution, but sometimes it's difficult to phrase the question properly. In this case you can post questions to forums on Reddit etc - you'd be amazed at the trivia that somebody out there is an expert on. Similarly, firms that provide services or goods that you need details about are often very willing to answer strange questions. I always start my email by explaining that I am a crime writer - the communications staff for large companies spend much of their time dealing with the same routine questions from the public. Something a bit different will often pique their interest. For my latest book, Out of Sight, I needed some specific guidance on the laws surrounding the drafting of a will. I found a firm that specialised in this and fired off an email on a Friday afternoon. A partner replied within a couple of hours, saying that they thought the question was fascinating and they'd get back to me. Sure enough, Monday morning I received their response. It was really lengthy and detailed, and they had clearly spent time looking up what I needed to know in their own time.  
For other precise facts, Wikipedia is a remarkable resource. I just finished writing a short story, and in the first draft, I blithely mentioned a life insurance company. Fortunately, I always flag anything like this with a comment to verify later. It turns out that not only did I have their name incorrect, it had also sold its life insurance business years before my book is set!
Finally, don't forget Facebook. I know nothing about guns, but there are dedicated writers forums populated by US cops who can tell you everything you need to know and more! If you have a wide and diverse group of friends, then sometimes it's worth posting the question and letting the FB hive mind do its thing.
Don't let the (inevitable) mistakes get you down.
How much effort you put into finding out these little factoids is entirely up to you, and I am well-aware that I am probably at the more obsessive end of the scale. It can be a tremendous time-suck, if you aren't careful.
Unfortunately, mistakes still occur, especially for things that you are convinced you know  - I was certain that I had the name of that insurance company correct, and was really only double-checking capitalisation and spelling, I had no idea it no longer sold life insurance.
Even if you are correct, there are plenty of readers out there who won't believe you (I had a recent surreal email exchange with an overseas reader who took exception to my pluralisation of a word, refusing to back down even when I cited the Collins dictionary). Some readers even write to authors to castigate them for giving incorrect directions for a fictional route between two places that only exist in the writer's imagination!
There will always be those who loudly proclaim on social media or review sites that an author's faux pas 'ruined the whole novel' and they had to 'put it down, never to read one of their books again'. Sometimes they call into question the author's attention to detail, accusing them of not bothering to engage the services of a proof-reader or, something that really irritates me, implying that the proof-reader is useless and unprofessional - they aren't, they're human.
Dig a little deeper and you'll find that such an over-reaction usually says more about the reviewer than your book. Often, they are using it as a platform to broadcast their supposed expertise on a niche subject that nobody else really cares about.
To be honest, aside from absolute howlers that are embarrassing, my advice is not to lie awake at night. If there is an opportunity to change the manuscript, then perhaps do so, if only to avoid having to reply repeatedly to the same questions on social media. Otherwise, wear it as a badge of honour. You aren't really a successful writer until you've had your first unjustified one star review!


How bothered are you by small inaccuracies? Do you have an obsessive attention to detail? What tiny details do you always strive to get correct?
As always, feel free to comment here or on social media.
Until next time,
Paul.

Relationships between characters are at the heart of all stories, and crime novels are no different. In this week's #TuesdayTip, I want to look at how we can write realistic relationships.
First of all, I firmly believe that you can't write a relationship unless you know the people that you are writing about. This is as true of minor, secondary characters, as it is of long-standing, series regulars. So before you start writing a scene, think about who will be taking part.
How two people interact depends on a range of factors.

• Their personal history (if they have one).
• The power balance between them (think about how you might bite your tongue when your boss says something really foolish, compared to when your best friend does something really asinine).
• If one individual needs something from the other (a police officer may nod sympathetically whilst listening to a murderer confessing, putting aside their personal revulsion to get to the truth).
• The public façade that each character wishes to portray to others (a guilty person in interview might try to come across as helpful and open; their interrogator may want to seem as though they are trying to help them out).
• Jealousy (the green-eyed monster can affect any relationship , whether it be sexual jealousy or plain old avarice).

With that in mind, it's worth considering the types of relationships that occur in real life.
Lovers / Spouses / Exes.
These relationships are so often at the heart of dramatic fiction, and for good reason. In a crime novel, where the aim is to dig below the surface, it's worth spending some time building up the layers for key couples/former couples.
(Note that I make no assumptions about whether these relationships are same sex, opposite sex, or non-gendered. I will be writing a future blog about writing LBGQT+ characters, but the questions below should be true of any relationship).
So ask yourself a few questions:

• How long have they been together?
• What is their relationship status?
• Are they committed/exclusive?
• Are they open with each other? Is there, or has there been, infidelity?
• Is there a power/financial imbalance?
• Are they happy? Is there abuse or anger or jealousy?
• What challenges are they facing/have they faced?

• If they are no longer together, how long were they together for?
• When and why did they break up? Did they ever get back together?
• Was it a happy relationship?
• Was it committed?
• Did they keep secrets from one another?
• How was the break-up? Was it mutual? Have they both accepted it and moved on?

Parent / child or between siblings.
These are amongst our closest relationships, rivalling even that between lovers and spouses. These people have known us for many years, and we have evolved and aged together. Even in close, loving relationships, there is often emotional baggage that will forever colour how we interact. They know what makes us tick, and what buttons to press. They have often seen a side of you that nobody else has, such as temper trantrums.
How have the relationships evolved? Do the chcaracters 'regress' to childhood patterns of behaviour when they meet up with them? Do old memories and feelings resurface?
Old friends.
Friends are like family - but different.
Think about the people you grew up with - they know all your secrets; including the ones that you kept from your family. They know about your likes and dislikes and what makes you laugh.
Are your characters still in touch, or have they perhaps drifted apart? What happens when they reunite? Again, do they regress?
Then there are new friends.
A new friendship group, perhaps as a result of moving, or going to university, can be an opportunity to reinvent yourself.
Would old acquaintances recognise the 'new' person, if they were a fly on the wall?
Then there are your work colleagues.
We often spend more waking hours in their company than we do friends and family. Sometimes they become best friends, other times they are people we (barely) tolerate. Even the most open and friendly colleague is probably showing you a different face than that seen by their closest loved ones. I am sometimes struck by how a colleague's social media posts often seem to be that of a complete stranger. Doubtless they feel the same way about me.
Casual acquaintances.
Is the relationship friendly, antagonistic or neutral? How did they meet? How often do they see each other? How much do they know about your character? Do they know things about the person that might be unexpected (eg something they overheard or saw)?
So, what if all these different people meet?
Weddings are unique occasions when two families and circles of friends meet, often for the first time. I've written before about how people often regress when they meet up with childhood friends. What happens when your character finds themself sitting on a table with people they went to school with, people who shared a flat with them as a student, and the people who know them primarily through work? How will your character deal with that?
In a crime novel, a police officer interviewing acquaintances of a victim or suspect might get different responses depending on who they interview. Who should they believe?

Things to keep in mind
Keep the relationship consistent - but remember, relationships evolve.
This is not a contradiction! For there to be a change in a relationship, there needs to be a catalyst. That catalyst could be something as inevitable as the passage of time, but as a rule if two workmates are warm and friendly one day, then cold the next, then something must have happened. This is the assumption that your readers will make, so take care not to lead them down the garden path by being careless - they won't appreciate it.
Don't forget the importance of relationships between secondary characters.
A couple of lines is all it takes, but it will help round out a character and make them realistic. The touch of a spouse's hand on their partner's shoulder can tell the reader lots about their relationship without ever being explicit.
Two people may have an entirely different view of their relationship.
There are plenty of people sideswiped by the unexpected ending of a relationship that they though was going fine. Or consider that sudden explosion of anger after a few too many at Christmas, when you realise that your constant 'joking' about your sister's weight was actually only funny to you...
Then of course there is jealousy or unrequited feelings.

So how can you write realistic relationships?
Observation is key:
Look at friends and family. Pay attention. Is there a relationship in your life, or someone you know, that matches the one that you are trying to write?
Of course, this comes with a big health warning - think carefully about how comfortable you (or they) will be if it becomes apparent who the character is based on.
For that reason, it may be safer to take note of how relationships are dealt with in books and on TV. Soap operas are pretty much nothing but relationships, but of course the quality and realism varies. Choose wisely! As a reader or viewer, you probably have a gut feeling for what works and what doesn't, so follow those instincts.

So, what are your thoughts about writing relationships? Are there any really good examples that you would recommend?
Feel free to comment below or on social media.
Until next time,
Paul

According to the file creation date on the Word document that would become the first draft of the book that would eventually be published as The Last Straw, DCI Warren Jones came into being on Tuesday 12th April 2011 - exactly ten years ago today. So for this reason, I decided to bring forward this week's #TuesdayTip and put together an article sharing some of that journey and what I've learned in those ten years.
For a quicker, more light-hearted read, you may want to check out my post on the HQ Stories blog, where I catalogue the 10 things I've learned in 10 years.
https://www.hqstories.co.uk/2021/04/08/ten-things-paul-gitsham-has-learnt-in-ten-years/ 


Your debut novel probably won't be the first book you have attempted to write.
An oft-quoted saying can be paraphrased as 'the first million words don't count'.
Whilst there are exceptions to every rule, most authors have at least one previous attempt locked away in a drawer somewhere. I have several. Some are literally in a drawer - I became quite the expert at purloining blank exercise books from school for my scribblings*, and these unfortunate attempts will never see the light of day. Neither will the three hidden on my hard drive.
Yet none of these were a waste of time. Writing is like any other skill. You need to practise, and whilst a million words seems like a lot, when you add up those abandoned manuscripts, the various short stories and essays I've written for creative writing classes, and my rambling missives on social media, I'll bet it isn't far off.
But, The Last Straw was the first novel I completed.
The key point I am making is do not despair at a perceived lack of progress. Your first finished book is just the visible point of a very big pyramid.
 (*For the avoidance of doubt, I pilfered these exercise books when I was a pupil, not as a teacher twenty years later!)
Titles come and titles go.
The title of my first book was The Straw That Broke The Camel's Back.
It was clever, fitted the story perfectly and highly original. It was also ridiculously long.
Take a look at the titles of a typical crime fiction novel and you'll see why my publishers promptly renamed it The Last Straw. If nothing else, at least that fits on the cover!
Since then I have published a further ten titles - all of them follow the loose theme of a play on a well known phrase. I'd love to take credit for these titles, but really I can't. Naming a book is an art form in its own right and only a few are mine. No Smoke Without Fire, Forgive Me Father, Blood Is Thicker Than Water and At First Glance are the only names that stuck. The rest have either been tweaked by my publisher or are entirely a product of their marketing department.  Aside from a couple of times where I have fought my corner, I've generally been content to accept the wisdom of those more experienced than I. 
And so do names!
I've written previous articles on how to name characters (TuesdayTips 31, 32 & 33). But don't let that fool you. Since day one, I've found choosing the perfect name for characters almost impossible. When I started writing The Last Straw, the two lead characters' names were place-holders - Smith and Jones. Fans of British comedy will know why that pairing was never going to be the final choice. As it happens, I became very attached to Warren Jones, but Tony Smith became Tony Sutton  - a popular surname in Essex, the county from where he comes. Other characters in that manuscript changed in the final draft. With the benefit of hindsight, I would go back and tweak the names of a few of the series regulars - some are very similar to each other - but I'm stuck with them now, and I've grown to like them.
Finishing the book is just the start.
First of all, if you've just completed your first draft, congratulations! Seriously, give yourself a pat on the back.
My best friend, upon hearing that I had completed The Straw That Broke The Camel's Back, told me I should be proud of myself. 'Do you know how many people have started but never finished a novel'? And he was right. Probably hundreds of thousands of people have ideas for a book. Tens of thousands have tried to write it. Yet only a small number actually get to type The End.
Even if that's the final step of your journey, you have accomplished something that many people attempt, but never quite manage.
But that first draft is just that. By the time I was ready to shyly ask some close friends and family to have a look at my book, it had gone through months of revisions. That first draft was completed at the beginning of November 2011 - a little over 6 1/2 months after I first started writing it, but it was the best part of a year before I bought my copy of the Writer & Artists Year Book and started submitting to agents and publishers.
Rejection, rejection, rejection.
Aside from a lucky few, almost all writers have a pile of rejection slips (or more likely unanswered emails) evidencing their attempts to get an agent and/or publisher. It's not personal. There are a million reasons why you aren't signed. The chances are good that it has nothing to do with your writing! Agents and publishers have very clear ideas about what they are looking for at any given time, and it can be something as simple as the fact that they have just signed a writer similar to yourself - if you'd submitted before them, they could have taken you on instead. Keep on plugging away!
Back in 2012, I was still a full-time school teacher and self-publishing was in its infancy. Many authors were starting to take advantage of the new opportunities offered by Kindle and forging very successful careers. Some are extremely well-respected today and have earned an impressive following. But many of the tools and services that exist now were not available, and I just didn't have the time to do all the hard work that publishers do when it comes to editing and polishing a book, choosing a cover, typesetting, converting and uploading to Kindle, then marketing it etc.
It would have been a fascinating project to take on, but I wanted to spend my precious free hours writing more books and so traditional publishing was the best route for me. If I were starting today, perhaps I would have chosen differently, but I don't dwell on that . 
Publishing the first book gets in the way of writing the next one!
After finishing book 1, I was buzzing so much I promptly started on book 2. But that soon ground to a halt when my first beta readers gave their thoughts. There were months of work to be done on book 1 before I could start submitting it. The same thing happened with book 3; feedback from book 2 came in and I had to put that manuscript to one side. Nevertheless, by the time I finally got the call in summer 2013, from a new, digital-first publisher. I was half-way through book 3. They offered me a three-book deal. Now I had to juggle writing book 3 with editing books 1 and 2 again as my publisher sent them back for revisions and rewrites.
Some novelists only produce a handful of books during their career, with a gap of years between them. They finish a book, publish it, promote it and then start thinking about what to write next. For an ongoing series, momentum is the key to building a following. And so you find yourself stepping onto a treadmill; many writers I know are working on three books simultaneously: completing the edits for the upcoming book, writing the next in the series and planning the following book. 
Publishers change.
The publishing industry is very dynamic. Personnel come and go constantly, accepting promotions within their organisation or moving to a different publishing house. The traditional concentration of the industry in central London can make such career changes quite easy. Even the publisher itself can change.
My original publisher was Carina UK (their logo can be seen on the original editions of my first four books). Carina was a digital-first imprint of Harlequin, a publishing house known primarily for its women-oriented fiction, including the famous romantic fiction imprint, Mills & Boon.
I vividly remember my only visit to their headquarters in Richmond. I was buzzed into the office and upon reaching the first floor was confronted by a sea of pink, a massive M&B logo and a room full of women.
"Anyone expecting a delivery?" was how my presence was announced by the receptionist.
"Actually, I'm an author," I said.
Now, it's a myth that all romance writers are women - I know quite a few male authors of romantic fiction, but they usually hide behind their initials or pen names, so I can forgive her assumption.
"I'm with Carina."
"Ah, that makes sense," she said, pointing towards a corner of the room that had been painted the distinctive blue that they still use today. Back then, I was one of only a handful of male authors, and even fewer crime writers, working for the fledgling imprint - something that changed rapidly over the coming years.
After my first four books were published, it was all change. Harlequin was bought by HarperCollins. The Carina UK imprint (which shared its name with a different imprint in the US) was renamed, along with the rest of Harlequin and became HQ Digital (later HQ Stories as they started to publish more physical books and audiobooks), retaining its distinctive blue branding. For obvious reasons, they kept Mills & Boon as it was, given its name recognition and heritage.
Since then, I have had many more books published with HQ and have had several editors over the years. It's always sad when they move on, but change is a part of life, and I have always forged enjoyable and productive partnerships with their successors.
Covers aren't as unique as you think.
One of the lovely traditions when releasing a new book is the cover reveal. I had mine for Out Of Sight just last week. If you are with a traditional publisher, then the chances are it will have been cooked up by the design team (or whoever they subcontract to). There's no question that there are certain tropes within the genre.  A recent joke doing the rounds on Facebook was asking if anyone knows who the woman in the red raincoat is that features on so many covers, since she probably needs counselling!
When choosing the cover, there is quite often some dialogue with the publisher, and you may be asked your opinion. For a series, there will be an attempt to unify the fonts, colour palette and layout to allow for a consistent branding. I have been very fortunate over the years, with my publisher completely changing the covers of my first four books after a few years to make a more distinctive look as the series expanded.
All well and good, but there is a little secret...
The original cover for my second book, No Smoke Without Fire, perfectly encapsulated a key scene in the book. I loved it. So imagine my horror when a few months later, I spotted the exact same cover image on a different book. The title and genre were different, but they'd even used similar fonts! I checked the publication date and it had been released about a month after mine. Plagiarism! I sent an urgent email to my publisher...
Well it turns out that generally speaking, they don't have teams of photographers scouring the world for that perfect image... Instead they use a stock photo from a database and then modify it. Ten minutes with Google reverse image look-up revealed that the picture had been uploaded to one of the major stock image databases a couple of months before publication date - roughly about the time that our respective cover designers will have been choosing the perfect image...
Show me the money!
Everyone has heard of the six, seven or even eight figure advance. It usually helps if you are a celebrity. Unfortunately, the reality is different. Only a select few authors get to sign contracts for life-changing sums of money. In fact, surveys have shown that median income for writers is now far below that needed to live on if it is your sole source of income and it appears to be declining. And most of that income is derived not from advances, rather royalties on books sold.
I remember well the excitement and anticipation of my first royalty cheque. At the time, Harlequin paid its authors quarterly, so this cheque would be a bumper sum covering three whole months of sales.
£50.60 for 52 copies sold.
The following quarter was a breath-taking £217.60 as 242 copies landed on Kindles... Since then, things have picked up, and whilst sales will always be up and down, all my titles continue to sell. The annual release of a new book also renews interest in earlier entries in the series.
But you know what? Whilst I am grateful that I earn enough from writing that I have been able to reduce the hours in my day job to part-time, I couldn't stop writing about Warren if I wanted to. Over the past ten years, he and his team have become like friends to me and no longer chronicling his adventures would leave a gaping hole in my life. All that being said, if Netflix are reading this, please don't be shy, my email address is on the image at the top of he page...
And finally, whilst we are on the subject... Amazon Sales Rankings tell you nothing of any value! Obviously, a book in the top ten of the paid book chart is selling more copies than one languishing around the 500,000 mark. But the algorithm used to calculate your sales ranking each hour is a closely-guarded trade secret that takes into account everything from actual sales in the past hour to historic sales data over an unspecified period, the outside temperature and the colour of Jeff Bezo's underwear last Tuesday. Unfortunately, because rankings are relative to other books, yours depends on others' performance as much as yours. There are services that attempt to use the hourly changes in the rankings to calculate when sales occur, but Amazon deliberately makes it difficult for them to work accurately. I suspect this might be because authors publishing directly via Amazon have privileged access to real-time sales data, one of the key selling points for their services.


So there you have it. Ten years since I started writing DCI Warren Jones and just over seven years since The Last Straw was published. A further ten novels and novellas have since been written, with the seventh full-length, Out of Sight, just a couple of months away, and more are in the pipeline. 

Happy Warren Jones day!

Easter egg:
1. an artificial chocolate egg or decorated hard-boiled egg given at Easter.
2. an unexpected or undocumented feature in a piece of computer software or on a DVD, included as a joke or a bonus.
Definition from Oxford Languages.
The term Easter Egg was first used to describe a hidden message in a 1979 Atari video game. Since then its usage has expanded somewhat, and here I am going to extend it further to series novels and broaden the scope of the original meaning.
Why should you consider including them?
One of the joys of reading a series of novels is the sense of familiarity that they evoke. Familiar characters, well-known locations, and even in-jokes, can make a reader's return to your fictional world all the more rewarding. I left university over twenty years ago. In the intervening years, I have kept contact with a handful of good friends and former flatmates and we have done our best to try and meet up for a weekend at least once a year. In that time we've moved on: marriages, kids, grey hair and proper grown-up jobs, yet when we get together it's as if we are all in our early twenties again. Old jokes resurface, well-worn anecdotes and otherwise forgotten stories come back and I feel a comforting warmth. Over the years, partners that didn't know us back then have joined us and I often wonder what they must think. I know that my fiancée sees a side of me that she doesn't witness in our daily existence, and I imagine it is the same for the others.
I feel the same when the latest book in a favourite series is released and I spot the little asides and Easter eggs that the author has included.
So here are some of the reasons it's worth having them.
It keeps readers returning.
As much as I enjoy a good standalone with new characters to get to know, I also like revisiting old friends. Are there character quirks that your readers will look out for, such as favourite music? Is there a regular antagonist that your character will butt heads with? Is there something that they will do that they shouldn't? In Harlan Coben's Myron Bolitar series, one of the series regulars, Win, will usually do or say something that again has you questioning if he is actually a psychopath, even if he is a 'good guy'. I look forward to seeing what he'll do in each new novel. Successful TV series that last for many seasons often use these as hooks to retain their viewers' loyalty.
It makes your readers feel part of the 'club'.  
The inclusion of a few regular tropes can make loyal readers feel like they are privy to a small secret. Somebody reading one of my DCI Warren Jones books for the first time may find Warren's exasperation over his colleagues' avoidance of using the honesty jar to pay for their communal coffee an amusing aside. Those who have followed the series from the start will know to look out for that scene, hopefully remembering it from different books and looking forward to seeing how I include it this time.
It helps remind readers what they are reading.
There are several dozen police procedurals released every year. All are different, but all have undoubted similarities, especially if the writer tries to adhere to accuracy. The inclusion of these little vignettes can give the series its own unique identity.

• Spends time brooding on a balcony over-looking Los Angeles at night, listening to Jazz - that'll be Harry Bosch.
• Takes time out to have a pint and do The Times cryptic crossword - that'll be Morse.
• Carefully dismantles a sandwich or a burger to discard the salad - that'll be Warren Jones.    

It rewards rereading.
It can be a lot of fun going back to an earlier book in a series, and these little Easter eggs can provide little ah-ha moments as you spot something that you maybe skimmed past the first time, but which now has more resonance.
Material for a prequel or a short story.
Many authors have dabbled with prequels - going back to the early part of their main protagonist's career or life. This can provide a great opportunity to see the genesis of a character's quirks, or the start of an established tradition in your books. It's fun for the writer and fun for the reader.
Setting up future books or plot lines.
In one of my recent books, a long-established scene became part of the investigation. A variation on this scene had appeared in every book, and this novel was no different. It probably slipped under the radar for most readers, with regulars logging its expected appearance and moving on. Hopefully, they felt some recognition when they realised that I'd used it to smuggle in a plot point.


The pitfalls:
Easter eggs should be treats for the regular reader, but shouldn't exclude those new to the series.
Resist the urge to assume that everyone reading will be familiar with (or remember) previous references and hang a plot point on it. You risk people feeling confused and cheated if they can't work out how your detective realised that the text message supposedly sent from their colleague was a fake because they had used punctuation and their spelling was correct, when every other book had made a joke of their garbled communications.
Nobody likes to feel they aren't part of the club.
Despite our best efforts, I've no doubt that the partners of my university friends have at times felt bemused or even excluded slightly as we all roll around guffawing at some story that is really only funny if you were there. Try not to include too many in-jokes that will make new readers feel that they are missing something. The chances are it will diminish their pleasure and make it less likely that they read more in the series.
Don't try too hard to shoehorn them in.
There may be times that it is just not plausible for a regular scene to take place. There may be a highly amusing scene in every book where two characters go to ever increasing lengths to secure their favoured parking spot. But if this book is set away from the station, engineering the narrative so that this scene can appear may impact the book as a whole.


What are your views on Easter eggs? Do you have any good examples from favourite authors (no spoilers!)?
Feel free to comment here or on social media.
Until next time,
Paul.