Have done 2 studies of feet at two different sessions. Both 20 min poses. In truth, to do feet justice you can't really do the rest of the body as well in that time. So I focus on this one bit and to hell with the person attached to them.
This was part of a pose from life drawing the other day. Wasn't sure what to draw so focused on the hands holding the foot. Not what I intended to draw, have flattened the image out too graphic, but kind of like it anyway.
Mind you, I am glad he did because it made for a great pose. I would have never drawn a knee that high up in relation to the rest of the body if I hadn't seen it.