Lots of them are kinda very detail things, but these are put in a right place and right time, then boom! our animation makes "reality".
- Think about what leads what. And drag follows.
- Do not forget over shoot.
- Do not make just A to B action. Make a break down.
- Do not move things just same time. It makes your animation "Robotic"
- Think about characters motivation.
- Think about character's physicality, Is he fat or not, Is he muscularity or not....etc.
- 8 frame is a 4 beats
I know these are very basics and every boos talk this. But the point is you should put these note at "Right time and Right place". And I also know, It is not easy...