Caricature drawing is an art: the main things to aim for are achieving a recognisable likeness, and developing a style that is both yours and looks good. Many artists take years to tick all three of these boxes, and this tutorial is no substitute for good old-fashioned practice to improve your caricatures.
However, computers can really aid the process, and are invaluable in making it all a bit quicker and easier - which is a lifesaver if you're on a deadline. I prefer to use Adobe Photoshop and Corel Painter as they are bitmap graphics applications, and thus most closely resemble the feel of natural drawing. Vector programs tend to correct subtleties of line for you, and it's the subtleties that can make or break a likeness.
