Today's results were created using a rasp and drywall tool. The process was broadcast live on http://www.ustream.tv/channel/tutorial%3A-how-to-sculpt-in-clay---artistsculptor
Here you can see where the eye-sockets were created. The legs will be formed after the torso has reached the desired shape.
The drywall tool worked well on the Styrofoam. The only draw back is that it creates giant size snow flakes. As I was working I was thinking snow, but the room temperature told a different story, it was in the 90's. So much for positive thinking.