Allow me to share my top ten tips for writing crime fiction and thrillers that can please the reader making publishers start groping because of their chequebooks.
1) Know the market.
Read very widely. Numerous authors as possible, less many books. If you have read one book by Patricia Cornwell or Linwood Barclay, then proceed. You know their shtick. Learn what else is out there. Which means also reading the classics, having the history of the genre, and reading lots of fiction in translation too. Additionally, it means reading the kind of non-fiction. If you're writing political espionage thrillers, by way of example, you need to know the political, military and security bacground If you don't, your readers will - and you'll be caught out.
2) Understand where the leading edge lies.
The largest names (eg: Coben, Rankin, Reichs) are certainly not the most current. They built their reputations years back. Try to locate the sexiest (biggest selling, most praised, state-of-the-art, prize winning) debut novels. That is what editors are buying today. Which is the market you're competing in.
3) Don't merely trot out the cliches.
You've got a murderer have you? A terrorist bomb plot? Be tough with ourselves. These things are tired old cliches. They're able to work if you handle them in a new or dazzling way, but the old ways are not enough.
4) Get complex. Your plot almost certainly needs a brain-aching level of complexity, and a surprising number of well-planned, well-executed twists. Because modern crime authors are getting to be really good at developing complex but plausible plots, and because modern thriller writers have become so adept at delivering a continuous chain of impossible-to-see-it-coming twists, you can't afford to be less than devilishly clever yourself. With rare exceptions, simple no longer sells.
5) Stay with the darkness.
Your book should be dark and tough. That's your entry ticket for the genre. What you do there is very varied, but cute, cosy crime is certainly a limited market now. In order to write cosy crime, then expect a smaller readership and meagre sales.
6) Do not forget jeopardy.
Crime novels now can also be thrillers. It's not OK for the detective to resolve the mystery and explain all of it to a hushed and respectful audience. However, (s)he's got to stay fear of his/her life. It offers to be white knuckle in addition to intellectually satisfying.
7) Focus on character.
Crime and thriller plots can be forgettable, and often feel very samey anyway. Characters, conversely, never leave us: Holmes, Marlowe, Elvis Cole, Hannibal Lecter. If you discover a strong character, and do everything else reasonably competently, then you definitely quite likely have fiction that'll sell.
8) Write well!
Bad writing will, without doubt kill your chances of success. And quite right too. You don't need to be flowery. You do have to be completely competent.
9) Be economical.
Thrillers have to be taut. Check your book for needless chapters, your chapters for needless paragraphs, your paragraps for needless sentences, plus your sentences for needless words. Then do everything over again. Twice.
10) Be perfectionist.
Good isn't good enough. Dazzling is the target. Being tough yourself is the essential first ingredient. Getting another individual to be tough together with you is quite possibly the second.
I said ten tips, didn't I? What the heck, here's an eleventh:
11) Don't stop trying.
Be persistent. You improve by doing. You'll improve. Think about building your skills, engaging using the industry, or getting editorial advice. All of the things will increase your maturity as an author. Now write that thriller, polish it - and sell it. Best of luck!