Hands and faces are easy for me. I often heard people say that they are difficult to draw but I was already drawiwing them well when I heard that. I feel that nothing is more difficult than anything else is to draw.
I agree... Hands are hard. This is my best so far, but the proportions are off here and there. And I'm still having trouble with those little wrinkles on the back of the hand. The little lines on the nails, and the little hairs on the back of the fingers.
Years ago in an art class I took my instructor had us draw our hands. We did two different sets. Both drawings were done larger than life on 18x24 paper. The first hand she allowed us to draw as detailed as we could within the class period. The second hand she made us draw without looking at the drawing. We just looked at our hand while we were drawing. That was a toughie. I still have the drawings somewhere.