An option that works for me (although not for every pair of pants) is to use no buckle stretch belts like these. They are a lot more comfortable and hold up my pants better than regular belts. In fact, I've pretty much stopped using regular belts altogether unless the situation calls for it. These stretch belts can be dressed up as well and look great on a pair of chinos or dress pants. Granted they are not perfect and really depend on how many belt loops your pants have and how robust the loops are. For most situations though they work fine. They aren't exactly high quality but at least they are cheap to replace.