Hello There! After looking at your drawing I think you managed to get the overall shape of the foot to look quite good, I think you should work on making your shading more meaningful like put more shadin in darker areas and lighter shadin lighter one rather than shading the whole thing, but I can see you've already started doing that with the darkness near the bottom of the foot, I think using lighter lines when drawing the skin fold would make the drawing more effective, on the foot that's flat you have good toe rendering but I think you could improve the toenail on the foot drawing most to the left, great job!
