Teaching Animation and Story-Visual Language here in Vancouver BC at VANarts, we have the students shoot reference for their animation tests for various assignments. The knowing how to use the reference is one of the lessons to learn. The reference can help explain to the artist how the body parts are being effected as the body moves through the motions. The weight shifts from one hip to another. The balance of the body etc etc.
But following the reference too close will result in animation looking too much like live action, too rotoscoped.
If the scene requires the use of live action reference, the trick is to take the needed information from the reference and then put the reference away. { Don't throw it away as you may need to look back at it again. } Using the reference in the earlier stages, you then push the idea and make it animated. Not relying on the reference alone to dictate the performance. You have the information from the reference, now take it and be creative and push for the scene to be more entertaining than the live action. I discuss this more to the students as we go forward in the course.
I put together a few of my notes regarding my approach as i quickly scan a person hitting a pose. These notes are somewhat the order that my mind goes through as i take in all the angles of a persons body as i take down the information in my head. This is how i do my quick sketches as i draw someone on the bus or in a line at starbucks etc. This check list goes by very fast as the person may move to another position and i have to remember the angles from memory.
Using a great photo from Buddy Scalera { beautiful photo library for Artists - click his name to go to his site } - I broke down the quick steps I use as I scan a pose that someone has made.
I know these notes may not always be correct, as it depends on the actual position of the body, but in this example I am just using this one pose to go through the steps.