I assume you do sketches or pre-drawings before the actual video tape. How much time do you use on the preparation of each piece you make like this?
Also, I see you decide to draw in very detailed segments instead of working it over like a whole entity, and even through that process, you're able to keep the proportions perfect. Normally, I'd think you were using sketch marks to help place facial features, but I can't see any on the paper you use. Are you simply playing by eye to hand, or is the marks you use too weak to be picked up by the camera?