Miku Hatsune_Sakura

Okay, so first off is the line work. Considering that you make your work using a mouse, I'm totally astounded by your effort to accomplish this and come up with a decent line work! Though some may have missed their designated targets, it does not mess up the whole image.
Second is the coloring, since you made a fan-art, color theory is not an issue anymore and I did notice that you didn't use the common "bucket" method which is a plus factor for me.
For the final result or the outcome of the image itself, I do recommend to practice PICASA frequently, it is a pretty decent tool (even I use it) to tune some things like the awkward background bloom, the color highlights and the global image temperature setting, and may I add the somewhat strange white color from miku's mouth (please don't take it seriously).

So all-in-all, this is a fine work for a mouse user. It would be Deviously challenging for me to see you wield a graphic tablet someday (and I hope you will).