If a traditional outline may be too restrictive for you, consider mapping. This organizing alternative will enable you to create a visual map of your key ideas. Unlike an outline, the map doesn't require you to immediately decide the importance of various topics. You simply plug them in as they come to your head and this allows you to work on various points simultaneously.
The map is pretty easy to use. The main topic is placed in the center circle of the map. Then you draw a few spokes out of the circle (think about a bicycle wheel). The spokes represent key ideas which then have a series of supporting branches that have additional details. As with traditional outlines, if you don't have at least two supporting points, you should either cover that information within another topic or eliminate it. On the flip side, you shouldn't have more than three supporting points per topic. Just keep it simple.
Figure 1.0 (SCORE, 2001)