This is a thinner version of The Dopplehanger, and I've added some "hook plus bar" pieces. These should work okay for lighter items that you want to hook in your closet like headphones, headsets, coils of wire, etc. If they break, try the original DoppleHanger where the cross-section of the hooks is 10mmx12mm (these are 8mmx8mm).
As with the original, pieces attach using #4 machine screws (no nuts required). You should be able to attach a hook to a hook_plus_bar piece using a #4 x 5/8" or longer.
I left the holes open in case you want to use longer screws to reinforce the bar.