Here's some more stuff. I'm working on improving speed and precision.
The sketches are a bit messy, as I was focusing on understanding the "halfway to black" system through value studies and getting used to sketching (with minimal clean-up) spline surfaces in perspective. I ended up buying most of Scott Robertson's instructional DVDs (except the one with airplanes) - working through them now.
Been producing about 50 force sketches a day for Mike Mattesi's class, but everything still looks way too crappy for public display. I hope I'll get better in the coming weeks.
I'll be posting more soon.