Over the last year I have experimented with at least a dozen hip belts, mostly home made. Drawing any firm conclusions from my testing has been elusive....but I'll give it a try.
Belt plus buckle can range in weight from about two ounces to over 12 ounces (and probably higher).
My most confortable belt was at the lower range and made of a nylon mesh without any padding. The key to comfort was the fit. It fit snugly all around my waist with no gaps on the top or bottom. It had a slightly conical shape and that is why it fit so well. I used two 5/8" buckles on the front so the entire belt was about 2 ounces. The mesh allowed for moisture to escape so I wasn't all wet under the belt as I would have been with a waterproof one.
Most of the heavy padded ones were comfortable but at a price weight wise. Some of them weighed as much or more than my pack and frame.
I couldn't predict, ahead of time, which belts might work best. It takes me at least a couple of hours on the trail with a full pack to determine what works. On the last trip I took along 3 different belts and switched them during the 3 day hike. Most belts feel good when first put on.
A simple belt to make is one out of 2" wide polypro or nylon webbing with a two inch dual adjusting quick release buckle. The lightest I've made is out of 2" velcro that folds back onto itself instead of a buckle. The hardest to make are the thick padded ones. My sewing machine has some trouble with the foam. The easiest way to get a belt is to find one at a second hand store.