What I like about using shapes is that I can depict the internal anatomy of a subject in much greater detail. In this sketch, I tried exploring the anatomy of the foot further, even extrapolating shapes where there were none in the original photograph. The circle to the right of the big toe (top foot) for example was extrapolated but still based on the contours of the photograph and on knowledge of anatomy. Some of these extra shapes really made the foot come to life, for me. I particular like the large circle that outlines the heel of the top foot. I had trouble defining the heel in my previous sketch, and I think this shape really did the trick.

I also think the proportions in this sketch look much closer to the actual photograph. The upper part of the bottom leg looks a bit off, but besides that the feet and ankles look surprisingly accurate. I think there is room for improvement in the way I drew the toes on the bottom foot, however. The toes seem too detached from the foot, most likely because they are enclosed ellipses instead of open ones.