Today I am migraine free though sore, and I shall attempt productive procrastination instead of hiding in video games, tempting as it might be.
My love of mysteries goes way back to some of the first stories I remember reading, like Boxcar children mysteries, Nancy Drew, and the Hardy Boys as well as all the mystery shows and movies I used to watch, including Perry Mason and Diagnosis Murder and many, many others. By middle school, I’d read every Mary Higgins Clark book I could get my hands on and eagerly looked for others like them. I shifted later to a focus on historical mysteries, though I still enjoy mysteries of all sorts.
So I am speaking from a reader’s perspective but also as a writer (and I reread my own books, so there’s that, too) but probably not an expert to anyone’s mind.
I think the best thing to remember regardless of genre is to start with interesting characters.
I’m not saying they all have to be likeable or that they should be perfect, but I have a pretty good memory and if you asked me about some of those books I read even as a kid, I could tell you now what happens. Yet I reread my books several times (never creasing the spine, I might add) and would enjoy them. However, that is only possible when I as a reader am invested in seeing the characters reach the end of their journey. If I like them or their story is compelling, I can read it again and again.
If not, forget it, I’m not even sure I’d bother taking that book to a used bookstore.
Secondly, if you’re going to write a mystery, don’t get caught up in solving it all before you start.
You don’t have to know who did it. Part of the fun of reading is figuring it out, though I am usually good at predicting it, so if all the story has got going for it is that (again, I stress having good characterization,) it’s a miss. I generally start with a general sense of what happened and why.
As long as I have a motive, I can usually figure out the rest along the way. I’ve even changed suspects in the middle of the story as long as it felt genuine to the way things and characters were developing.
A mystery doesn’t have to be complicated.
Police shows have spoiled us by convincing us that crimes get solved in an hour or less (forty minutes these days.) And they add drama by adding more deaths. That isn’t necessary at all. I’m not saying avoid tension or suspense or not to have any cliffhangers or twists. That’s not it. There’s plenty people can do over the course of a plot that leads them to their ending that doesn’t need all the fancy stuff or a lot of drama. I love amnesia plots for being able to reveal things a bit at a time, but there’s life besides investigation. Let it happen to the characters and suddenly your ten chapter story is thirty-five and twenty thousand words becomes almost two hundred thousand and you wonder where the last two months of your life went.
(I am not kidding. I have lost track of how many times this has happened.)
The world of your mystery is just as important as your characters.
Are you writing in the present? The future? The past? Those things affect how your case develops and how your characters react to things. Nothing drives me crazier than a modern attitude slapped willy-nilly on a character from the past. I’m sorry, but no. They were most likely not progressive, they’d have strong opinions based on their time period, and it would not agree with your world view. It’s a thin line to walk with female characters, in particular, because you may want a strong one, but that goes against Victorian convention. Acknowledge that as she solves the mysteries, and it’s okay. Ignore it, and people like me who have a bit of a history interest are going to be frustrated. Also, remember technological limits. Or defy them by writing in the future. Or on another planet. I’ve got some of those.
Is the setting local or far away? Is the planet itself a big part of things? I have a story where the planet itself stores the memories of everyone that has ever lived on it and special people can access them. This changed their whole system of government and world, creating a lasting but fragile peace. That’s the thing, though, where people are effects how their story plays out, so don’t forget that when you’re making a case, it can change just by adding a “road” after “street.”
(Yes, Greeley, it is still ridiculous that there are street roads and street courts and street lanes. You are a strange city.)
Mysteries do not have to be horror shows.
You can tell a mystery story without a lot of gore or violence. This is my preference, and I believe they’re called “cozy mysteries.” If you want to tell the story with gore and violence, you can, too. That’s a valid choice. Still, the shock factor and a lot of violence aren’t necessary. Implication can do a lot. Fadeouts can be used to great effect.
Also… not every mystery is a murder mystery. Plenty of things are mysteries without being about murder.
Mysteries may require research. Strange research.
I admit I enjoy watching shows like Forensic Files and learning about how they solved crimes. That fascinates me, too. And I sometimes wonder when my browsing history will get me in trouble because I’m looking up odd things that would raise eyebrows at best. I also find inspiration in tragic stories I’ve read about and other true crime stuff.
Be prepared to look into random things you never thought you’d want to know and wish you’d never seen a photograph of, ever.
Mysteries do not have be solved by law enforcement professionals, though this is common and usually amateur detectives have someone on the legal end that helps them.
If you can find a realistic way of making an amateur sleuth work, roll with it. Or maybe the mystery is one ordinary people get caught up in, and that’s interesting, too, as much as I like detective shows. I’ve got a mix of both kinds of stories, and I like them all. It can be a bit of a risk to go with the amateur even if the regular cops seem a bit overdone or cliche. An amateur who makes all the police look like fools walks a thin line. One who has unrealistic abilities and insights is not enjoyable to read about. Fandom would call them a Mary Sue/Gary Stu, and that’s become a real insult over the years.
And now I’m drawing a blank on other things I’ve learned as a reader/writer, but there are more things I could discuss if my brain hadn’t stopped working. These are also general pointers, so if someone had something more specific to ask about, they could.