I carry a sketchbook in my purse. I pulled the sketchbook out as I was seated at a bus stop today and sketched the scene across the street from where I sat. When the bus arrived, I wished I had more time to draw, and realize now, since I carry the sketchbook with me when I go out, I can work on the sketch again the next time I am at that bus stop. There's a reason it's called a sketchbook and not a finished work book!