Loner Yanagi
You have nice and clean lines and your coloring doesn't go out of them. This is very good. I would suggest that you use guidelines to try to work on the head shape a bit more. The top of the head seems a bit flat on the first one. As for the coloring a little more work on lighting and shading can help. Have you tried using references when practicing?
Thanks for the advice! As for the head thing, recently I've been drawing a sort of guideline for the rough size of the entire head (instead of just drawing the chin and working from there, like I usually do) and drawing the top of the hair above that line, so the head isn't as flat or small at the top.
I usually don't use references unless I'm really stuck, and I don't normally shade my drawings, so I don't get as much practice with lighting as I should.
sweatdrop