There are alot of tutorials on hands but are there any on feet?
Hands are pretty staight forward compared to toes, what i mean is toes can be very different to each other, look at your girlfriends feet and see how her toes squash into eachother because she wears high heals, (if you don't have a girlfriend I apologise for reminding you 
Some toes can be half hidden under toes next to it, look at your toes what bizarre shapes they are?
Just a thought.
P.s Before you ask i don't have a foot fetish.