Try something that happened to you or one of your friends. Or something that would never happen to you and explore all the possibilities. If you start with one or two characters, you can map out a whole town. Sometimes things just pop into your head. Write down all your ideas, because it sucks to lose one if you need it later. And try to make your notes clear so that you understand them later. I get inspired by dreams and I have to keep a pad next to my bed to scribble things, but sometimes I don't understand my own shorthand. Best of luck!