You are doing pretty much everything right in my opinion, the only critique i can give is to try shading it and getting it more realistic unless that is your style.
Yeah it defintitely looks a bit more fluid, just keep practicing accuracy and try using your shoulder a bit more while sitting.
I really dont see anything you could improve on gesture wise, from now i think you should try working on the hard details, making it look like proper figure drawing, a soft body instead of the rough shape.