1. Take the book you love -- the one you've read over and over again, even though you know exactly what's going to happen next--and this time read it as a writer.
Notice your favorite parts. What do you love about them? Is it the suspense? The relationship changes? The characters figure something out? Maybe it's the point where they fall in love. Or maybe you just love the writing style throughout. Whatever those favorite parts are, try to imitate them as you write your own unique story. Don't always worry about writing a book--that can be overwhelming to think about. Write a scene with your own created characters that imitates what you love about that favorite book.
2. Don't be afraid to put your characters in grave danger.
3. Think of the one thing your character would never, ever do. Now make her do it. And see what happens.