. . . of this head? I’ve had no prob. with the eyes, I tried modeling the mouth in a symmeler fashion, but it turned out horrible!
Modude,
Have you seen this tutorial?
http://wiki.blender.org/index.php/BSoD/Introduction_to_Character_Animation
In particular - this page?
http://wiki.blender.org/index.php/BSoD/Introduction_to_Character_Animation/Creating_the_mouth
Best of Luck!