The Uncanny Valley Book Text

Things that puts us in the uncanny valley?

Eyes

Lack of eye jitter (small, darty movements of two or three frames when someone is looking at something).
Cross eyed or wall-eyed eyes; these eyes generally appear to be unfocused. You always need to be looking somewhere. (wax dummies, toy dolls)
Wavering focus of the eyes; eyes not looking at a consistent target. (Not looking at something when you expect them to be looking. e.g. Not looking at someone when being spoken to.)
Glassed over eyes. No normal eye looks like glass.
If the eyes always move with the head when the head rotates, it looks robotic.
When characters don't blink at all, it looks odd. The average person blinks once every five seconds.

Face

Changes in facial expression that seem too slow, or are late.
No one has a symmetrical face so “perfect” faces look wrong. a lot of people have one side of their face smaller than the other.
Only one side of the face is moving; a common feature in stroke victims.
When what they are saying does not sync up with there mouth.

Body

Tips to keep you out of the valley

Micro Expressions. Small, quick and subtle expressions give a lot of personality and emotion to a character.
Nostril Flares. Believe it or not those bad boys move! But don't over do them otherwise they will seem un-natural.
Be careful when moving facial shapes individually. One movement on the face will cause another movement from something else i.e everything is connected.
Don't over-enunciate. No one over does it when they talk. It is subtle and second nature. (A baby or someone speaking a new language will be different. Cartoony characters can sometimes get away with this)
Don't forget swallows, gulps and neck tightens. If its a male his adams apple should move when he talks/swallows.
Most peoples heads don't stay still for long periods of time. Don't just leave the head static, try and break the regularity of even movements.

Rotate head to follow eyes, not the other way round. Remember the head moves because of the eyes.
Look for key places to widen and flare the eyes. Eyes can also twitch in the lids and brows.
Funny enough the Jaw can move side to side and in and out as well as up and down.
Don't forget to breathe. Chest rise and falls are very important.
Smile with the eyes as much as you do the mouth. In a fake smile only the zymgomatic major muscle (cheek) which runs from the cheekbone to the corner of the lips, moves. So you don't need to worry about the eyes in those situations. But it is up to you to judge wether to be real or fake.
Finally make sure the expression on the face fits with the voice and what they are saying. If they are saying “I love you” they most likely wouldn't look angry.