I really like the hand sketches in the last image, you can see both the structure and the gesture and your stroke has some character while remaining quite clean. However, I think you would have done better, and I'm talking about all the sketches you've posted, to avoid shading for now, because instead of enhancing the shape it flattened and "dirtied" what were basically pretty good sketches. Sometimes it's better to do a little less. Keep up the good work on structure and gesturing.