Warmup Sketching
It is actually very enjoyable. Like warming up and stretching before the workout. I start doing this during my college years, in sketching class. It starts a with simple line sketch, may not be of anything. Straight lines accross the paper, then circles, and then odd shapes with shadings. Sometimes just start drawing something from imagination or something interesting on the web, magazine, etc. Sometimes it turn out to be something really neat. Then I would redraw it and film the process to share.