To learn how to draw feet, it is best to start from the side.
Exercise 1: First draw very lightly the angular example with the straight lines. Then you make the circumference rounder. The foot is here seen from the inside.
If you look at the foot from the outside, you can see the toes. You can see that nicely in these anatomical drawings by Dr. Paul Richer from 1910.
Exercise 2: It’s also good to be able to draw feet with their heel off the ground. Start very light again with the angular example on the left. Then draw the bend in the forefoot and make the outline rounder.
This way a danser might stand on his/her toes
Seen from the outside the toes are visible
Exercise 3: Draw a foot from the side as lightly as possible. Then give the foot socks, shoes or sandals. It’s lovely to see how in some examples the studies of a bare foot lead to realistic drawings of shoes/sandals on the same paper.
A pupil has given wings to her feet. Feet with wings belong to stories about the god Mercury from Greek and Roman mythology. Mercury always flew back and forth between the gods and men, hence the wings at his feet.
EXTRA: draw your own foot or someone else’s, possibly with a plain colored or gray sock. Try to suggest plasticity with shadow/hatching (= curves, concave and convex parts, folds etc.).