I realize that there is a technique, to organize and stimulus your idea. It is called Mind Map.
It seems weird at first look, to organize your idea in such a way. However, I do give it a try by using FreeMind.
Just after one and a half hour, I am able to draft out a big picture of the feature.
It seems that as you trying to break down your ideas into smaller chunks and document them down, more new ideas will be stimulus.
Great! Isn't it?