I see potential in you.
I believe you need to practice more anatomy and how to draw hands.
look at another people art and see what lines they use and where they use these lines in the drawing.
you have improved with heads and the proportions looks good, try practicing a bit more of painting and you will get a better result.
the way you must practice is copying images of references, this way you retain more information in your mind than just watching/reading.
Hope to see more drawings from you.
There