When it is time to begin a book, when the blank pages are waiting and the fountain pens have been filled, I recommend you make the barest of plans you can, just enough to aim at what you are setting out to do. Too little direction and you might miss Medicine Bow. Too much planning and you can talk yourself out of turning into the little unmarked road that leads to the left, along which may be the moment the whole journey will end up being about.
It helps to make a list of the stories you want to tell and events you want to describe or the things you want to say. I find it is better to make a list rather than an outline. A list makes me feel as though I am writing a book rather than taking a correspondence course.
I think it wise to leave enough room to ramble around between stops to see what is there to be discovered. Or perhaps to sit in a square and watch people go by. It will not hurt to drive down a long road and have to turn around.
I like to have enough of a plan to know when one might be well advised to turn west into the sunset or stop for the night. But I also need to give myself the freedom to add a chapter or throw one away, to add a story or save it for another day.
A writer can dutifully follow a well-reasoned outline and end up missing the point. A writer can complete the assignment she set for herself and still not write the work she meant to write.
– Robert Benson “Dancing on the Head of a Pen”