I have a few skirts I haven't gotten around to sewing elastic into yet (a technique that is beautifully described on Bellydancewithk.com, by the way, at this link:
http://www.bellydancewithk.com/bouti...readcasing.htm ). So when I need a quick fix I just use double-sided lingerie tape, and put some tape along the back, sides, and front. I go heavier on the back and sides because that's where the skirt tends to want to ooch its way down.