And I don't mean write a horror novel (unless that's your preferred genre).
Sometimes a book idea scares us. This fear centers on our feelings that we won't be able to write the book "right." Maybe it requires a lot of research, or the subject is controversial and you're afraid of stepping on toes. Maybe you just don't know how to get the idea across.
It's just "too hard" you tell yourself. You're not good enough to write that book yet, and you pick a safer idea.
Today I propose to you that instead of putting that idea away, you write it anyway. Write it despite thinking you're not a good enough writer to do it justice yet, or you don't know how to get the ideas across, or you feel yourself bumping up against your own weaknesses as a writer.
Do you normally write plot centered books, but you have a killer idea that you would love to write but it requires you to be able to write deep, complex, nuanced characters?
Write the book anyway. Even if you write the book and it sucks, you still learned something from the experience. You can still go back and fix your mistakes. You can make it suck less.
Or who knows. Maybe you write the book and it turns out to be the best thing you've ever written.
Pretend you're an old man/woman looking back on your life. You're sitting on your front porch, looking at your collection of published novels. You only have two days left to live. Is there a book you regret not writing? Is there an idea that keeps you up at night, but you tell yourself you're not ready to write it yet?
Don't let the fear of failure hold you back from writing the books of your heart.