I believe they look best cinched over a somewhat shapeless dress or with a skirt.
Garnet Hill Rivoli Wide Belt, $78
Here's a pretty amazing example of a wide waist belt over a simple dress from Garnet Hill (even though she's wearing it at her hips)
I think it may be time to buy a wide waist belt because lovely leather ones are on sale right now at Anthropologie for $9.95 and up. I've been following them at Anthropologie, Free People, Garnet Hill for months, and I've never seen leather ones this low.
Do I dare buy one? Will I manage to wear it? My dream would be that a belt like this makes a few items in my closet work that have never worked before.... or...
...knowing me: I may be forced to buy a dress or a skirt to go with my belt :-)
What about you? Do you own a wide waist belt? What have you styled it with?