Yes, a quick guide for who can't draw feet/soles yes i'm a bad teacher >_>
1) Make an "inregular rectangle" (lol). Draw the leg base (for ref.). Make only sketches, we'll erase in the end.
2) Make the "feet body" (lol). Draw all the curvatures of the foot (make it regular).
3) Now make the toes base. The toe length varies with the toes count (four toes = bigger toes). I'll start in "order of proximity" (what is the toe in front of everyone? I'll start with you!!). Make some irregular ellipses.
4) Make the connection. Turn the toes with the rest of the foot. Make some details.
5) Lineart! Done!
The perfect guide is... photography. Look at a photo then try to "reproduce" in a drawing. Training, training, training, training... when you can reproduce a photo, create some positions.
I hope it helps!! ^^