I had a little used hallway in my house, so I relocated the electronics, framed/drywalled a wall and door frame, installed a door, then designed a shelving system to better utilize the space. I modeled it up in 3D, transferred it to a 2D program to minimize waste, then built it. Pictures are better than words, so here you go....
Closet modeled with transparent walls for viewing clarity.
A closet where there used to be an empty, unused hallway.
The shelving installed in the closet.
The shelving being used.
There's a large, u-shaped shelf on the top for keeping things out of sight, a coat rack hanging off for hangar storage, a larger lower u-shelf, and 6 radiused shelves for lighter duty storage.