When I'm through, I know what I have to say. This is a strategy for thinking by disengaging from the subject. My wife, a fiction writer, gets her best ideas by taking long, hot baths. She doesn't try to think in the tub. She just soaks.
Ideas float in of their own volition.
Other people may take hikes, play basketball, or ride bikes. Still others may read novels or magazines. Idle thinking frees the mind for creative ideas. One of my students asked me if I thought television was bad for the mind. He said his father was always arguing that students in his day did more thinking than students today.