When I take the train in the morning, I've tried drawing what's around me but I'm chickening out lately. I'm too sleepy to feel brave and also, I worry about some people getting offended. So, what I've started to do is to cut out little pictures from magazines and copy them on the train ride. I can usually finish one of them in the time it takes to get to work. I can still get some practice working out proportions and composition and still keep my privacy intact.