Many animators use thumbnails as the starting point to their animation; here’s Glen Keane’s take on it if you’re interested. These are akin to gesture drawing; you’re trying to accurately describe the basic lines of force and action, without worrying about detailed features.
Here I actually looped a five second scene from “The Public Enemy,” in which James Cagney introduces Mae Clarke to some citrus, and jotted down what I thought were some of the key poses and actions. Then, because I’m all about mixing old and new, I timed it out using an iPhone app called Animation Timer, which notes the time in film frames every time you tap the screen.
Of course, the more I draw and observe out in the word, the better i’ll be able to make my characters “act.” In fact, today I took a few spare moments and scribbled thumbnail sketches of folks by the 72nd Street subway stop. Unfortunately, all I saw were people chatting on their cell phones, and virtually nobody wielding decorative slices of fruit.