Hello Pixophile.
I'll try to help you a bit.
First some things i think you did that i think are nice:
-You experimented with hue shifting on some parts.
-The angle of the head is really interesting, makes it feel intense
-The design is simple but interesting(She would make a cool game character)
And here's some things that you might want to try differently:
-You are being really conservative with your hue shifts and darker tones, try to be a little bolder.
-The lines inside the forms could be removed if you try to separate masses and forms with contrast.
-The background is really noisy, as is the hair.
-Try to keep the flow of the pixels in a soft logical pattern
-Your anatomy was a bit distorted so I moved some features and made the hand smaller.
Here's some notes I've made:

And here's a paint over I did to show you how I would change it:

Hope it helps.