Hi Gahpe
yuor studies look very clean. Line quality and that certain self confidence comic book contours need to have is already there and are nice to follow, actually.
My main suggestion would be to try something along the lines of gestures. If you search through the general anatomy forum stickies or the tutorial section there should be a wonderful tutorial by Rebeccak about gestures.
Gesture in this case does not only mean the pose of a hand or an expression of one part of the body - it’s more a general pose and a natural flow of weight, balance and energy which forms a strong figurative image.
A good section to practise the loose character of gestures is the sketchathon (in the tutorials and workshop section, IIRC) where you draw from reference photos within 15 mins. That way you don’t have the time to care about details or even categories like “right” or “wrong” - all you try to do is nail the gesture down.
Have fun!












