One of the easiest ways to buckle your own belt design is to re-use the buckles on canvas woven belts that do not seem to be popular anymore (as I see them at all the thrift stores for not too much money). You remove the belt 'ends' from the canvas (reuse the woven waste for purse handles), and re-stitch them on to the body of your belt.
I like it best when the body of the belt is a big curved rectangle three to four inches wide, and waist measurement long (minus the length of your buckle) so that the wide part curves across to the front of the body, ending in the skinny buckle harvested from the 'golf' belt. Stitch the up-cycled bucket onto each end of your belt body, using the holes that are already there, so you don't weaken the leather by adding more holes. An asymmetric shape is also nice, skinny on one side and wider on the other. If you curve the shape of the rectangle slightly, it will sit down further on your hips, which is much more flattering on most bodies than a tighter waist fit.