To me this move always looks best with a D ring belt, but it can also looks quite fly with a belt buckle as long as it isn't on some "everything's bigger in Texas" type vibe. As for how far you offset the belt, that is a personal choice. The Bastian models had it pulled over just before the first belt loop on the right side, but I prefer to go just pass said loop. It really doesn't matter all that much as long as you like how it looks and, most importantly, feel comfortable. Ultimately the look is unique and adds a nice streamlined look to the front of your pants.
Like most sprezzatura this is all about not being so obvious. After you wake up, put your pants on and shif your belt you probably should leave it alone for the rest of the day. If you start fiddling with it in public you are defeating the entire purpose, not to mention, as the day progresses and the belt shifts on it's own it will end up looking cooler anyway. I always find that sprezzatura works best when you pay attention to the details before you walk out the door, but once you do forget all about it. That way when someone tells you your belt is off you can look down, act surprised, say "whatever dude" and you won't be totally full of shit.