Okay, so I’ve talked a lot about writing what you know and how important that is, but it’s hard to offer practical examples so here’s one:
I lived in Hawaii for a while. Now, it just so happened to work out for the book I’m currently writing that four of my characters go on a weird, messed up vacation and Maui was the ideal destination. And let me just tell you, I’ve had a freakin’ blast writing about it because not only is it a great trip down memory lane, but there are things you’d never be able to describe about Maui unless you’d been there–like crawling up the side of a mountain in the dark in the jungle in a car with an engine that barely runs, wondering if you’re about to lose power completely and slide down a hill to your death. Or the way the whole island looks like it’s on fire when they burn the cane and how you have to close all the windows so you don’t wake up covered in ash in the morning. Or the absolutely unholy stench from the sugar factory that hangs over the airport. Or waking up and finding a lizard on the ceiling directly above your face. Or how you learn to just eat ants like a garnish because they’re fucking everywhere and there’s literally nothing you can do about it. Those kinds of details you really can’t manufacture. Now before you say, “But you lived in Hawaii, that’s so exciting, and my life is so boring, I don’t know anything” (because someone always says that), allow me to preempt you: this applies to everything and everywhere. Your high school, your hometown, that restaurant you worked in in West Covina. If you’ve ever worked a job or lived in a place or had a hobby where the details are familiar to you, you can write them with an authenticity that can’t possibly be faked, and that will add tremendous depth to your story, whatsoever it may be. It doesn’t matter if it’s not, on the surface, exciting. Authenticity in fiction is engaging and addictive, because that’s when a reader goes Wow. Yes. I can see that. Or even, I know EXACTLY that feeling. In some ways, the more mundane, the better. Because if you can do justice to a mundane experience, everyone else in the world who has had it will have an absolutely transcendent moment seeing it prose.
So. Write what you know. You know a lot more than you think.