Attached Link: http://www.erc.msstate.edu/~camen/thehumanhead/home.html

Well, it is generally best to start modeling the eyelids and surrounding areas; then move on to other prominent areas (e.g., mouth) and so on.

When modeling, it is a good idea to follow the muscle structure of the face. I included a good resource for this; just check the URL for detail. Try finding some muscle reference on the 'net, it'll come in really handy.

For your model, I'd suggest starting over and trying to follow the muscle structure.