Follow through and overlap.

 i was asked to draw a basic squirrel character design to demonstrate these techniques focusing mainly on the tails movement. I made the squirrels body movement quite quick and snappy which i think improves the the motion of the tail and adds character to this basic design.
The idea of over lap and follow through in this is that as the body lands the tail is still following behind, and when the squirrel takes off again the tail is landing behind him and overlapping the characters action and following through when the character stops, so once the characters body finally lands the tail still has to move into place.

 Squirrel!