Random troopers seems pretty easy. Storm/Snow/Scout gives you some decent variation without even leaving the OT (which I always hate to do). It is originaltrilogy.com after all. Rebel/imperial insignia would work too.

I’m inclined against any imperial images as a default, though. Some people can be strangely sensitive to being designated a “bad guy” on day 1, so I’d say rebel insignia.

The “standard” symbol of the rebellion was retrofitted onto the OT as a branding exercise, but there were actually lots of rebel insignia to choose from.