Exo

You really should do more work like this one, I think it came out pretty awesome.
Comments:
On future ones, explore more 'screen tone' type layers or transparancy's. Like the shading around her nose.
You have a great silouette going on, but if you squint it is pretty much just a triangle blob.
Add in tones or screens for more highlights, and fading back and forth to get more depth out of the great silouette you have going on.

Go for some backgrounds or foregrounds too! Even if they are just simple shades or line work. Think of where the character is, or what she/ he is doing, or going to do.
And place her in it.
I think you have a great piece here, and just some extras, and more depth too it, will really make it outstanding!
Good luck!