1) Don't try to hash-out your plot line with rational people. They will look at you like you're crazy and say something like, "But witches aren't real." <---people like this don't belong in my world.
2) Don't wait until the very last minute to come up with a last name for one of your characters. You'll end up naming them after things you see. Like John Pencil or John Coffee...or John Four-Baskets-Of-Laundry.
3) Don't drink and write. Coffee is your friend. It keeps you awake and energized so you can write that one scene where everyone is running around confused and crazy. Tequila? Not your friend (at least not when you need to write). Tequila makes you write sentences like "You look like a sad spaghetti noodle." True story. (See Ch. 34 in Anew)
4) Don't forget to eat. I know writers like to hole up in a cave and write all hunched over at their computers like they're mad scientists of words...but food is essential. Without it, you get delirious and start talking to inanimate objects. Like your computer. I'm pretty sure I had a fifteen minute argument with my Mac about "file space" that ended in tears. Hunger makes us crazy.
5) Don't let yourself get spooked! This one is fo sho! (That's my thug talk, right there.) It's scary to pour your time into creating a story and then release it to the public. It's truly terrifying. It's like taking all your clothes off in the mall (which I've never done, but I assume it's frightening. And weird. So, ya know, don't do that.) You have to commit! Throw your words down and smile! You just wrote a book. Hollaaaaa!!!!