As I'm looking at these pictures, I notice that your characters generally look... stiff. The bodies are typically standing up straight or perfectly horizontal (which makes them look rather unnatural and dynamicly-disabled). See if you could create more movement within your art pieces and when you create a character, do not make the spine a straight line. Spines are actually "S" shaped if you include the neck. Some type of curve is in order
xp Spine tutorial here to help you out!
[Link] I find the second picture to have a strange composition as well since I don't feel a sense of balance and that some of the visuals look odd since it's only done in granite, HB pencil.
One last final thing I think you should work on is folds in clothing. You seem to create creases in random places when it comes to pants or shirts so they look rather scarred up then baggy. Here's a great tutorial from DeviantART that may help you out!
[Link]Hope my critique has helped you! And good luck with your drawing skills
biggrin