Carlos Baena:

Keeping animation crisp:
(Reference: CGChar)

It's all on the Spacing and Timing of the character going from one pose to the other. If the character is only taking a few frames to go from one pose to the next, then it may need different cushioning than a move with more frames. No matter what, you'll need to add cushion to your moves, or else, you'll get pops all over the place, or mechanical types of moves. It's important to play with the timing to see what results you get. I could tell you right now, a pose A to a pose B in 10 frames will need about another 10 frames of Slow Out. But the truth is, every action is different. Every action fits a different mood, a different personality and so on. So you have to ask yourself those questions before animating the character, and the timing of the character will follow after that. I always try to add slow outs, even if we are talking for just a couple of frames. Nothing just stops unless it hits a wall.