For figure drawings, less is more. Try focussing, not so much on the details (hair, muslce tone, fat) but more on the expression and movement of the subject. Try drawing lines or shapes that symbolize parts of the body.
Something I found that helped me with understanding this stradegy was drawing a piece of paper. First, flat on a table (so just a square) then, imagine its a face, facing the right or left, so with curved lines at the top and bottom. Try using this site's face expression drawing tool but only draw the piece of paper. Really interesting results :-)
You're drawings are very good, you definitely understand drawing techniques and excecute them well.
Stay motivated!
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