Are you talking about the little graemlins and posting icons like this

?
I would say probably just simply MS Paint would work best to design it, because it has the simplest pixel-level editing. Since Win98SE (or Win98 Plus from First edition), Paint has been able to save in .GIF. As long as you stick with the major colors, you shouldn't have any problems. If you do run into problems, use Paint to design it, and then save it with a more specialized .GIF program like
Animagic .
Hope this helps.
---Skorpion