The sign for "better" starts in front
of the mouth (not actually touching) and comes out to the right a bit. (Assuming you are right handed).
The shape changes from a flat hand into an "A" hand with a loose thumb.
"BETTER" and "BEST" are actually versions of "GOOD."
Memory Aid: An interesting way to think of "BETTER" is as a combination of
"GOOD + ER," and "BEST" as a combination of "GOOD +
GOOD: (For more info, check out the "GOOD"
The sign for BEST makes a much bigger movement, and moves up.
The more you exaggerate this sign, the more your are emphasizing how much
better something is than the others thus it may dip down a bit for emphasis
prior to moving "way up."