It's been a while since I've perused your gallery, but I took a look today and this really stood out to me.

This is a very nice pic, overall. I think the main problems here are in the shading.

You seem to use softer brushes to shad with, and that can really take away from a piece. Try using harder brushes to get more depth. Also, some of the shading here just doesn't seem dramatic enough. What I mean is that in some places there's barely any shading when there should be a good deal more, and with darker shadows. The biggest are like this is the arms.

The only other thing I see here to crit is her wrists, which kinda look a little bulbous. Try to make the wrists flow seamlessly with the hands. There's a little bump of a bone on the outside of the wrist of a real hand, but you must be careful when you try to draw it.

I hope that helps! Overall it's very good.