hey, great job in that piece, one thing that i can see is that you tend to draw the face features a tad bit too big.
I drawn over it to point out the things i saw, one thing that i don't know is if you made the face from reference or use the imagination, so i did my based in your drawing, i tried to keep the distinguish features of the face, like the bigger zygomatic bone for exemple.
One tip i can give you is if the shading part is in the way, don't stress about it, since is not required for the construction phase of the head, is already hard as it is XD Again great job, keep at it!
Oh, and take everything i said with a grain of salt, i'm a beginner myself so i can be very wrong about stuff
