This one has been done multiple times, but...
Depends on the ladder, what are you trying to hang/store?
I have a couple of hooks on a couple of rafter ties in the garage an hang my extension ladder there lengthwise in the garage.
I have a couple of 6 footers and plan on building a shelf with a couple of angled wood plate for the two ladders to hang from by the top "step"
My 3' step ladder just sits leaning against something, and moves around depending on where I used it last.
