Sketching heels?

A few days ago, a friend of mine challenged me to draw heels. I never drawn heels before, so I thought it would be a good challenge. I feel that the first page on top was a good attempt with a few funky feet. I felt more comfortable with the 2nd and bottom pages.

What do you guys think? I may try some more shoe sketching this week.

they are deceptively difficult. Proportion and detail are paramount… like anything I guess. I have never mastered it.