Here's a nice piece I made this weekend:
I always have this idea of painting on cardboard boxes and never do, so as a result I have a ton of cardboard boxes sitting around my apartment. This weekend, I actually sat down and got to it, and I'm quite pleased with the results. The combination of black and white on brown, is both mellow and high contrast, and carboard has a natural texture and grain to it. It also has a very impermanent and gritty feel, which is another thing I really like. I'm going to have to make point to do this more often.