your last portrait came out a lot cleaner in terms of lines but you captured the depth much better in your earlier ones. try and find a blend in between that works for you. also when you draw contours, try and be looser, it looks as if you are trying to outline the figures rather than capture their form. if that makes any sense, try and pin point the mass. focus on weight and structure. the last ones read much better. just let go, they are only gestures, they are not meant to be perfect rather just enough to capture the essence of what you see.