The main thing I think you could focus on is your figure drawing, not like muscle strucutres and fancy-latin-words anatomy (that does help, though), but being able to draw characters in comfortable poses with strong lines of action. Best way to practice this is to go to a live figure drawing session, but those are expensive so instead you could ask a friend to model for you, or sketch people around town, or sketch people in a movie if none of those things work you could also use Pixelovely.com
Figure drawings should be quick and gestural, and the most important thing is capturing the rhythm of the model, feel free to completely ignore the details.
That said, it looks like you draw your figures in a variety of different poses and camera angles and that's really good. Keep doing that.