As far as how I save the gif files goes, I'm not really sure I understand wth is going on myself, I just tinker with it a little more now and pay attention to the preview window.
There are three or four settings that reall screw me up from time to time.
%transparency --- with gifs the pixel is visible or it isn't, but with my psp drawing they can be anywhere from 1 to a 100% transparent, what this does is tells it to make any pixel above a certain transparency level visible
Dithering --- Don't use it myself
Color Selection --- I use either Median Cut or Octree (WebSafe looks like crap in comarison 3/4 of the time)
#of colors --- When the file is too big, lowering the colors saving it, and then (only if it looks rough) running a smoothing pass with the retouch tool helps get the file size down and fixes any rough spots made by lowering the colors in the first place.
blending partially transparent pixels --- you can either use the existing color at full opacity, or blend it (at full opacity again) with a color of your choosing.
The biggest problem for me is when I have partially transparent pixels around the edges of the drawing, I have to play with the %transparency alot in those cases, and sometimes retouch spots, because it just won't look right.
I have Photoshop somewhere around here, I'll install it soon, and see what the differences are (can't remember specifics) so I can better help you Photoshop users with some techiques, though
I still have alot to learn myself