When you have an idea for a good story, write it down. Don't worry about the details, just capture the idea on paper in any fashion. The details will all come together as you create them. I recommend that you read a lot of books similar to the type you want to create. Learn the importance of understanding point of view, voice, past or present tense, and the structure of a good book...the beginning, the build up, and the conclusion. Write often, read often, and enjoy the challenge of bringing your own story to life on paper.