When writing a mystery/thriller book, you want to plan, and plan well. You should know how your story is going to end before it even begins. Mystery/thriller books are unlike any other genre of writing, you can't just go with the flow and hope for the best like you can with a romance novel. You need to allow the hints and events to slowly but surely add up to your ultimate conclusion, and to do that you need to map out everything that you plan on happening before you even execute your story. This will not only make the writing process so much easier, but it will also give your antagonist much more depth behind it.

Do you remember the last movie you watched where you found yourself sweating a lot and eating popcorn so much that you didn't even notice that you're acting this way? Or maybe the book you are reading that's been playing with your mind ever since it gotten creepy and mysterious?

Well, what do you think are the strategies of the author upon making those masterpieces? The connection accumulating as you go further on the story; didn't you notice that you yourself have been hooked without really knowing why?

First things first, if you wanted to have these kinds of effects on your readers, you need to know your audience. Know your writing style. If you're into classics, use old English. If you are more like a 21st Century writer, use the usual language that the millennials are using nowadays. It will make your story feel relatable for them.

Secondly, you need to pique the interest of the reader. With this in mind, you need to create a blurb or a brief description of your story that will catch their attention. Make it short, precise, and leave a mysterious line at the end of it. Let them be intrigued on your story.

Thirdly, give your characters remarkable personalities to the point that the readers will distinguish from one another, their assets and their vulnerabilities. This will add twist on your story.

Fourthly, create an imaginary labyrinth and suggest a series of possibilities along the story. Yes, you have the plot inside your mind but you need to play with your readers' hunches. You need to mislead them in a way that they might come into different conclusions but in fact, it was just a pixel of a bigger picture. You need to shock them with your plot twist.

Lastly, submerge yourself into the characters. Think like them. Feel what they feel. Visualize yourself as a killer if you must and figure out what will you do to accomplish your plans. Or, be a detective. Trace the steps of the killer until you get to the truth.

When thinking about the mystery books I love most, one thing about them stands out. The author was not afraid to traumatize their readers. One of the things I love about writing mystery/thrillers is building strong, meaningful relationships between my main character and the secondary characters, then pulling the rug out from under the reader. As writers, we often despise the thought of killing the characters we have lovingly crafted, or allowing them to commit heinous acts, but in truth, that is where the gold usually hides. What better way to hit the reader in the feels than by making your main character's beloved childhood sweetheart a raging homicidal maniac behind closed doors? Or the police detective's own child committing the crimes he is investigating? Or, a big twist and one I adore, making your main character the bad guy all along!

Writing with reckless abandon is not only fun but bolsters further creativity. Just when you think you've taken it dark enough, take it one step deeper! Add that extra twist, make two characters evil, betray your main character in ways only an utterly horrible person would. After all, it is your book so go for the throat! Be the bad guy. Write from a place that says you're not afraid to scare the pants of your readers, a place that says, "Oh, you think that was bad? Just WAIT until you see what comes next!" Leave a mark that keeps your readers wanting more, even if it means they must read your books while hiding under their bed.

Study and learn the genre, maybe read some successful books from the genre to get the feel of how a good mystery/thriller is written, study how the author describes their story, especially the atmosphere and the tension.

Planning the story is key, don't just plan the beginning and wing it the whole way. I did this when I started writing and it doesn't work, the consistency will fall apart. It's okay to improvise less important features in the story, but don't improvise the beginning, climax or conclusion.

When you begin writing your characters, don't jut give a character a name and toss them into the story, readers will notice this. Planning a good, relatable character takes time, and planning is what is going to make your story good and it is more then worth it.

Give your protagonist a motivation for their what they do, what is their goal? why are they determined to reach it? It it apart of what they do, or is it a personal matter? This goes for the antagonist to, don't make them 'evil' for the sake of it, give them a motivation for why they do what they do that they think is justified in their own mind.

Start with an opening that will 'hook' your readers, In thrillers, it's especially important because you need to start with action from the get-go. Often times starting with a news report or neighbourhood rumour is a good way to accomplish this.

Don't be afraid to make things difficult or hard for your protagonist, throw hardships their way then the time calls. This will help build the tension you want to convey throughout your story and make the protagonist's eventual success much more satisfying for the readers. So, put your characters in jeopardy by having dangerous situations come at them from unexpected places! Make their trusted allies turn on them seemingly out of the blue, make things go very wrong for your protagonist, these twists will have your readers wanting more!

When writing my mystery, I use red herrings. A red herring is a writing tool used to distract the reader from who may have done it. The reader trusts their instinct and picks out the suspect until another character comes in the story with a different motive. From this point, the reader is misled and reads deeper into the story to find the truth.