My pen and ink drawings came from doodling in class while my teachers were talking. It started in just the side margins of the paper and slowly spread to the entire page at some point. My teachers must have thought I was taking some really good notes by the serious concentration on my face.  It goes back as far as I can remember, probably back to grammar school. The drawings come completely from my subconscious, I start with a shape and just keep letting my hand just flow with the pen until it stops.