Wanted to use the door of my locker at work to help store things after forgetting my car keys and having to go back and get them because I didn't see them at the bottom of my locker. Couldn't find what I was looking for on here so I designed one a few years ago, but my method of connecting pieces together was pretty shoddy. It broke quickly and has been glued together ever since until it finally broke beyond glue. Being so weak I never uploaded it but I think this will work at lot better since I used dove tail joints instead of whatever concoction I thought was great at the time.

Crude design, but my locker isn't a showcase.

Top plate is the hanger plate, #1, meant to be hung through the vent slits found in most metal lockers.
Then use whatever utility plate you like, there are only two at the moment but I will add more if this system actually works out.
Use a intermediate plate, #3, between utility plates, this allows you to daisy chain utility plates to your heart's content... or your plastics failure, whichever comes first.

Meant to be printed as oriented, sloped some facets to help with bridging, added some hard point supports to help with adhesion, shouldn't need to add supports when slicing.

I'll add the fancy stuff like pictures and more plates if this pans out.

9-29-24
I used this until it broke after a couple years then didn't think much of it. Suddenly one day I see a 3d printed part hanging out of someones locker at work and thought, "There is no way someone actually found this, printed it, and is using it where I work." So I kept an eye out who the locker belonged to and when I finally caught him, I'll be darned if it wasn't this design from five years ago. So that was cool.
To celebrate I added the 2 compartment plate I never added. I still need to print that one to see if it will print and work.