I might spend 100 pages trying to get to know the world I'm writing about: its contours, who are my main characters, what are their relationships to each other, and just trying to get a sense of what and who this book is about. Usually around that point of 100 pages, I start to feel like I'm lost, I have too much material, it's time to start making some choices. It's typically at that point that I sit down and try to make a formal outline and winnow out what's not working and what I'm most interested in, where the story seems to be going.
Michael ChabonAll the preparation in the world doesn't avail you if you can't make that imaginative leap and put yourself in the position of the characters you've created, to imagine what it's like to be somebody else.
Michael Chabon