Anthropomorphic Drawing
Charcoal on paper. After some years of classes I ended up in a study group where the poses went on for ever, and some of the models were terrible, but it was inexpensive. So I used to keep myself amused by drawing a bit of the model, and then a different bit, then turning the paper etc. the challenge was to get all the bits joined as if they were meant to be like that. It became an interesting way to work.