Ladies, I am deeply appreciative of your comments -- they were very helpful!
Lantana, I have very few belts to choose from. I've got a plain black leather one with simple silver buckle, and I use this one to hold up my pants, if need be. I've got a black leather studded one that works if worn across my hips, if I want to look particularly rock n' roll, and I've just acquired a stretchy black fabric one. That's pretty much it! I really am a total amateur when it comes to belts.
Mo and Vix, I just love that toggle belt that you both posted pics of! That's just the kind of thing that would look good on me (although it doesn't count as a 'waist belt' because it would sit more on my hips and form an elongating V). But I'm on the lookout for something like that. Where did you get yours?
Kate, I like what you said about 'embracing your natural waist'. I've been wearing my new stretchy cameo belt pretty high up, because that's where it wants to go, and I've decided that it looks fine. No use pretending it's lower!
Diana, I think a belt like your animal print one, with the narrow bit at the front, might work for me too. Goodness! All the possibilities. Should be fun!