How does one crochet cheeks?

The pattern Im doing has just a round circle for a head so the face is flat. How do I crochet in cheeks? I think one has to decrease in places and make the eye line. I dont know where the eye line would be or where the increase/decreases should go. Im very confused. Does one put the eyes above or below the eye line? I want to make the doll more three dimensional. Thank you!

Vikavikaz

Thank you.