It's a simple fact that it takes less time to draw mouths and eyes than it does to draw bodies and limbs. So, by creating a set of happy and sad mouths for lip-synching, it's possible to cut down on the need for time-consuming whole-body animation, while still maintaining convincing character acting. In short: the head does all the work so the body shouldn't need to.
This project gives you an overview of the process I use for this, from creating original pencil sketches through to a finished animation. To accomplish this, it will help if you already have a good understanding of both Flash and Illustrator.
