1) READ! READ! and then go READ some more! The best writers I know are also phenomenal readers. I also listen to books on tape when I go on long car trips with my kids. I thought Harry Potter was brilliant when I read it, but listening to Stephen Fry read it (we got the English version) I was even more impressed by JK Rowling's imagination and her skill with words. Same with "Double Fudge" by Judy Blume - one of our family favorites. We listened to it on the way down to Washington, D.C. so of course we had to visit the U.S. Mint! ("Money, Money, Money, I love Money Money Money")
2) Take lots of showers. My characters always seem to talk to me when I'm in the shower. (One of the things I like about being a writer is that when I tell my agent that my characters are talking to me in the shower, she says, "Great!" instead of putting me in a straightjacket and shipping me off to the funny farm.) Not sure if it's the running water that makes them so chatty. But I always seem to get snippets of dialog when I'm in the shower. Problem is, I can't take a notebook and pen in with me, so I have to remember to write things down when I get out.
3) Can't think about what to write about? Use your own feelings and experiences. A lot of the things Jussy feels and thinks about in "Confessions of A Closet Catholic" are things that I was grappling with in middle and high school. The circumstances might be different, but the feelings are the same. And I have to confess - the obsession with chocolate is very autobiographical...I come from a long line of chocoholics!
4) Get to know your character. What do does he/she like and dislike? What does your character want the most in the world? And what is stopping him or her from getting it? You might not use every little detail when you write, but it helps to know about your character before you start. Even so, you'll be surprised where your characters lead you by the time you finish!
5) Write a little bit EVERY DAY! Set yourself an achievable daily word count and try to stick to it. Writing every day helps to keep your characters' voices chattering away in your head. If you ignore them for too long they tend to get all huffy and stop speaking to you - at least that's the case with my characters. They're a temperamental lot.