The 5 x 5 method

This is a method I've used to generate ideas.  You can do it in the car or when walking. Suppose you have five major areas in which to generate ideas. You take the first one, and think of five ideas about it.  On your next walk, take the second chapter (area, etc...) and develop 5 ideas about that one. At the end of the process you will have 25 ideas that you can then pare down to 16, by eliminating one areas and keeping four of the five best ideas in the other ones.