First of all, good design and color choice.
I have some pointers, first the anatomy isnt correct at all,
the arms looks like rectangles, you should give rythim on your drawings
using curves, mostly straight on one side and curve on the other as
most anatomy of humans. I put an example of better anatomy in red over
your painting.
second, the pose and angle of the body isnt dynamic,
you mirrored the pose and it turns out boring. I put an example of
more dynamic pose in light red, on the side.
thrid, your hair isnt stylish at all, try to mimic some features of
oher styles, I see you dont have a light source, light is everywhere.
All hairs have shadows, saturation and highlights, your hair is with random
highlights everywhere and no shadow, or even a variation of hue.
I have painted on top an example of what a hair should look like.
I hope you can understand what I am saying and use it in future.