Equipment used was a Wacom 12 inch graphics Tablet & photoshop 4 on a Power PC Macintosh. Monitor resolution was 1152x870 displaying thousands of colors.

Obviously you're going to need an initial image. Could be a drawing, scan,in color or not, but at some stage it needs to go to more or less a line art sort of thing.

This is the original doodle which eventually became the b/w gif I posted of the same image. This sketch is done on the tablet using a 2 pixel airbrush tool at about 20% opacity. Those faint lines you see are previous layers, with their opacity turned down, so you can gradually work up to a reasonable drawing without a billion lines everywhere.. The line art version was produced as as separate layer with 100%, 5 pxl paintbrush tool, set so the pressure sensitivity of the tablet produces a change in line weight (size), but not opacity. Then you simply get rid of the underlying layers. This should give you a clean only black or transparent image to start from. If you want to proceed to phase 2 (about post #7) where we lose the line art altogether, you don't have to be _so_ concerned with getting rid of the intermediate gray pixels ( so you have a really clean image), but it helps.

If you're scanning, I use greyscale and high res to get maximun detail, adjust contrast, then select out all dubious pixel colors, then crank down the brightness to get again, only black and transparent. Same goes for jpegs gleaned from the web (I did a test with a Taylor post earlier today). This image (and all subsequent) are posted at 100% working size, which is about 1 1/2 - 2 times the planned final image size.

Usual rules apply: garbage in; gargabe out. Make the original drawing both as good and as clean as possible. The better each stage, the better each subsequent one.