We have a bunkhouse style TT and have been using the lower one for storage.
It was getting kind of jumbled up and my wife asked if I could do something about it.
I had a sheet of OSB and a 1 X 4 out in the garage and this is what I came up with.
The slots are big enough for our toaster oven/air fryer, ice maker and her sewing machine, with just enough room to slide some TP in on the end.
The 1 X 4 is to keep small totes from sliding around on top.