The other thing in my sculpture course was stonework. Now that I can live with. You're limited by the shape, grain, and quality of the stone, you're limited by your tools, you're limited by your ability and vision, etc...it's easy to see what to make within the confines of those limitations. Plus it's fun. Gets out the aggression well. Here are some links on it. Also here, here, especially here, here, here, here, and here. Trust me, it's easier and more fun than you think. I mean, you smash a rock with a hammer! How cool is that?