Shioko

Nice composition, lots of action, it reminds me of a comic book cover.
Your lighting focuses more on specular highlights than diffusion and shadow. I think it would jump off the page more if you changed the lighting angle (assuming jumping off the page is what you are going for)
I wish it had a background, that would help the jump factor as well.
The hair is in one big clump and doesn't add a lot of character.
Her left shoulder seems to bulge a little, I think she needs more bicep.
Her right knee seems to be twisted 90 degrees.

Keep working, you defiantly have above average artistic skill.
If you love it and work hard someday you will be a master.