Brow Shapes:

# brows are almost as important as the eyes. If the eyes are the windows to the soul, the brows are the curtains

# keep the brows connected. If you move one, the other should react in some way

# the inner third of the brow is where most of the animation should occur

# try to mimic the shape of the brows and the upper eyelids

# what is the best eyebrow pose to communicate what the character is thinking/feeling

# make sure the eyebrow pose is true to the character ( how can you plus the personality)

Brow Timing:

# the brows should lead the eye change by a frame or so, the eyes should lead the head

# characters will generally hold an eyebrow pose until they have a change in thought

# brows tend to move faster than other parts of the body, so the ease in and out's can be smaller.