I've been reading Rad Sechrist's How-To blog (http://radhowto.blogspot.com/), since I've been working to get better at drawing quickly and clearly for storyboarding. One of the exercises that he mentions is making copies from screencaps of classic Disney movies, since the quality of their draftsmanship is unquestionable. Copying from the masters is an exercise suggested for any medium.
I'd never understood the point of doing this, but Rad explains in a way that I finally understood-- while you copy from what's good while paying attention to the foundations, you learn a right way to do things that you may not have come up with on your own, like ways to draw hands, folds, eyes and noses, while paying attention to underlying structure, flow and overall design.
Perhaps now, after a year of figure drawing and other art foundations at Sheridan, I am able to see these better than before and that's why it makes sense to me now.
Here are a few I've been doing. Of course I had to start with a couple with one of my favorite Disney movies of all time, Great Mouse Detective.
Basil, Ratigan and Mr. Flaversham are (c) Disney. All these are copying (not tracing) from screencaps at http://disneyscreencaps.com