It's very important to break your facial features down into separate files. While I retraced the face as a whole piece, when copy-pasting into new files for the individual parts I pulled it apart even further. Remember that the face is the most expressive part of the human body, and has dozens of nuances of individual movement. Eyebrows move independently of the eyes; eyeballs move independently of eyelids, lips move independently of tongue. There are also various layers; I have the bases of the eyes, for example, and then the eyeball would layer on top of that--but then I made separate parts for both of the upper eyelids, both to cover the eyeballs correctly and so that Lex can blink or close his eyes. The same goes for opening and closing the mouth; the lips are made separately, and would layer over the open mouth piece, which would show past the lips when they move.
My entire parts bin, when finished, has only 64 kb of files--and that includes the 10kb detailed background that I exported. Make your files no larger than they need to be.
