In his "Learn Writing with Uncle Jim" posts, James Macdonald urges aspiring writers to type out the first chapter of a favorite novel - the idea being that doing so will give you a ground-level, word-by-word inside look at what makes the prose tick. It's amazing what you can find out when you're forced to engage with a work at that level of detail, when every choice the author made of what to include (or leave out!) is brought into the light. Much like when visual-arts students copy the paintings of the Great Masters, there are secrets of technique and composition that open up for the apprentice who's willing to reproduce a respected work one line at a time.
In a similar vein, my friend Vishal has taken on a project for himself to learn the techniques of comics: he's redrawing Alan Moore and Dave Gibbons' Watchmen a page at a time. He talks about his rationale for choosing this particular work, and his approach to this vast and ambitious undertaking, here. I look forward to seeing what further discoveries he makes in the course of it.
(For those of you with an interest in seeing what makes comics in particular work on their own terms, I recommend Scott McCloud's Understanding Comics as an excellent starting point. Not all of his theory is waterproof, but his insights about the practice of creating workable sequential art are really spot-on, and potentially applicable outside of comics as well.)
ETA: Vishal, from correspondence, says this about the kind of insights this process can provide: "When you actually have to draw it you start to notice all kinds of things you never did before. Pacing is a big revelation. One of our most famous directors from the 40s, Raj Kapoor is known to have said something along the lines of, 'You want to learn Editing? Read a comic book' -- and he was right. That first page, for instance, with the 'slow-zoom' out from the button on the street. Bereft of Rorshach's monologue going through your head, it becomes this almost hypnotic progression. I'm sure that in the movie they'll actually do a slow zoom, but it might actually work better if they pulled back in cuts. Also, somehow you never noticed quite what a lonely, tired old man the Comedian was until you start drawing the interior accoutrements."