Well.. Hello this is my first head
Please say me, what problems or mistakes i made on this Thank you.
Btw if u have an idea how to improve that - u are welcome

It's really nice but the mouth is too plain. Add details. 7/10

It's a little to plain like KaiTyga said. 6.5/10. If you add some more black on top and other dark colors, it would sell for 1k-3k.