Nearly all movies these days, an certainly all movies that involve animation or special effects, are plotted out visually beforehand using storyboards; a comic strip like series of drawings, often done simply in markers, showing the basic on screen composition and sequences of action.
There is a nice Flickr set of early storyboards from the original Star Wars movie, early enough that the design of the “pirate ship” in some sequences is very different from the eventual design of the Millenium Falcon.
The art credit for most of these is apparently Joe Johnston.
[Via Kottke]
