Here's a slideshow of the stages of the drawings
I had critiques with both Tim and Michelle. Their comments were really helpful and give me a lot to work on for my future drawings:
I need to think about "packing the form" - the human body is made of irregularly shaped packed forms arranged on curves. I need to remember to define the top edges of those forms, the edges facing the light, as much as the bottom edges, the edges facing away from the light.
Also, in both these drawings I've over-modeled in the light. All the darkest shadow is on the side of the model turned way from me, so almost everything I saw was in the light. In my zeal for modeling form I made everything too dark.
I also need to practice seeing the forms arranged in fans arcing off of changes of direction on the contour.
Finally, I need to emphasize structure and solidity, otherwise my approach with soft gradation tends to look too wispy. I agree. I am not interested in making pretty drawings, I want to make strong drawings.
Not only have I learned a lot about drawing from this workshop, but also my expectations for myself have been raised in the process. I have a vision for how well I will someday be able to draw, a vision for how I could draw with a lot of practice and investigation, and it's far more developed than I ever expected of myself before.