All of my Star Wars miniatures are based on round washers, covered with medium size model railroad ballast, and painted a sandy tan color. A detailed description of how to make bases is in my general Painting and Basing Techniques section.
It has become standard to paint or flock all miniature bases green, but I didn't want these figures to look like they were all standing on a miniature golf course. I also wanted to avoid painting different figures with different colored bases, trying to match them all to their different movie scenes. I did not want to paint the probe droid's base snowy white, only to have it look strange when I used it in a jungle scenario. I wanted a single color that would look right in any kind of terrain--desert, forest, snow, or indoors.
I settled on a sand color, though I think grey might also work well. The color I chose matches the camel color felt I use as the base for my Tatooine terrain. Tan also is a logical color for a forest floor and for rock outcrops or bare patches of earth in snowy tundra or any other outdoor terrain. I think the tan bases look reasonably natural on a green or white table, and they don't stand out as much as a green base when placed on a high-tech interior room floor.
Back to my Star Wars Miniatures Gallery.