Also, I just took an tutorial from stanwinstonschool.com that really helped refine my techniques and process. I can't even hold a candle to the master level stuff they have going on there.
EDIT: Just a note. Yup, it's supposed to be creepy. A teeth baring head on a pole doesn't have much wiggle room around creepy.
Step 1: Basic Proportions
1. The eyes are in the middle of the head. For real, the forehead and hair are the full top half. Fold a face in half and the eyes are right there on the crease.
2. If you fold that same face in quarters, the fold above the eyes is the hair line and the fold below is the bottom of the nose.
3. So now that you're all into folding faces, fold it into thirds lengthwise. The eyes are in the middle of the two lines. The mouth stretches the middle third.
4. If you have two eyes (which most of us do), an imaginary third eye of the same size should fit between them.
5. Ears line up with the middle of the eye and the bottom of the nose.
6. In profile, the brow and chin line up, and the ears are in the middle of the head.
So this is a jumping off point. Each face is different in one way or another, but if you start here, people won't immediately say "dude, that isn't right."
AND this is just for drawing. When you get into the 3D world of sculpture there are a million other things that come into play as the head turns.
Also, you know, check out a mirror. You've got one. Take a look.
Step 2: Skull
Step 3: Block Out Features
NOTE: Do not even think about putting on ears or eye balls yet. The ears come last, otherwise you end up squishing them over and over while you mess with the rest of the face.
Step 4: Adding Muscle and Flab
If you're having trouble understanding the shapes, as I do, think about each section as something you're more familiar touching. Such as, the cheek is a triangle with the roundness of a mango; the nose above the nostril is a tarp to the cheek; between the eyebrow and eyelid is a cashew...
Remember, your not doing details yet, just shapes, so try to keep yourself from digging into wrinkles or line work. It's the shapes and how they come together that sell the artwork in the end.
Step 5: Teeth, Eyes and Ears
Eyeballs: Make some round bits of off-white clay that are equal in size. I made about six to be sure I'd get two close enough to the same. Then, if you're using polymer clay, bake them before putting them into the sockets. Now, using small bits of clay, create the upper and lower lid.
Ears: Now that everything is close to finished, attach the ears. I'm terrible at ears. Use references.
Step 6: Fine Detailing
THE END: And there you go. Brand new head. Now give it an amazing paint job and start in on the next one. You can only get better from here.