I’ve always had had a belt holder that hangs on the hanger rod in my closet and found it annoying. You have to make sure the belt weight is distributed or it hangs crooked, which annoys my designer sensibilities (well, not that much-- my belt-holder-induced stress level hasn’t been too debilitating!). I also have a handful of those little white collar stays for dress shirts, so I added a little tray for those. The closet system I was mounting it to was fiber board (which handles nails and screws poorly), so I used dowels and a bit of wood glue.
Normally I try to make everything pretty, but this is going in a place in my closet that no one will ever see, so I just went with trusty draftboard. You could use pretty materials if you cared (I’d do maple and white acrylic). Also note that 2 of the 8 belt slots are wider-- I had two chunkier belts that needed it.
Here’s a bad picture of it (with 1 belt so you can see it in action):
Discourse is having issues with SVGs, so here’s a dropbox link: https://www.dropbox.com/s/a3yt5cxh6tsdaf9/belt-complete.svg?dl=0