The line-art is pretty good. It has a few flaws, but what artist doesn't have flaws?
The one thing I noticed is that you might want to be more observant at how you shade and highlight. I see some parts of the drawings at where you've shaded even if it should be highlighted.
This problem/confusion is easily solved, though. 3nodding
When you're drawing (dunno if you make the line-art in PS or draw'em by hand. let's say PS) make sure that you have a lot of space that you ain't going to use. That way you can make a dot that will act as the source of light.
Any surface facing away from the source will be shaded and every surface facing the light will be highlighted. ^^
On top of that you could try practising some anatomy to make sure you shade in a way that brings out the right shapes.
I hope this helps.
Sincerely,
//Varulvsnatt
