Some are things like line of action and silhouette. But some are more typical things that we've been drilled into over the years that we have to unlearn...things like reality and logic...things that will restrict the pose from being the best it can be.
I read this book once called "The Animation's survival Kit" by Richard Williams...now you'll notice if you read between the lines that all his tutors, teachers and mentors all told him that he was being too technical...and I agree with them...a lot of the examples in the book were too focused on proving a formula then successfully showing what they really trying to do.
Although I did find one thing I still think is important, unfortunately he did explain it too much in a technical way.
He calls it "Breaking the Joint"
I call it "Dismemberment" or "Disjointedness"
It's removes the expection of trying to force realism into a pose that could jeopardise the whole direction or intension of the pose and what it stands for.
I hope this example helps push the understanding of what I'm trying to say. This is a true fact, why is the chin pushed into an unusual way? Well mainly in cartoons you have a larger range then simply trying to copy reality. Sometimes you have to shift the character around to read more clearly.
Have a look at the two together: Ok, technically if we changed the head/cranium around on the second one it could still work but ultimately the message behind it has gone now...Reality has robbed it of it's direction and punch.
Because the head isn't leaning back, the kick has lost a lot of energy out of it... Here is one of the drawings I've posted earlier this week, to be honest...it lacks a lot of energy to it and the pose is scrambled.Logically you'd think a character would do this if they were going to take a swing and I must admit...It has some good factors about it but...you risk throwing away part of his expression in the action, yes you see some of it is in the eyes but it's not clear. This pose I like best, you get more of a pull behind the pose, more direction but you don't throw away the expression, all your throwing away is how you'd do it logically which in truth no one really cares about to begin with.You know it needs to be a big swing because most of the line of action is in the bat and arms of the character
The direction is improved, the action is simple and clear...you don't need reality in interfere with entertainment.
"Focus on the result...Not the Formula"