In the past, I've always made creative mounts/hangers. Frankly, it depends on the models design.
Most of the time, I end up doing something like this:
Some kits allow for convenient hanging points. With some thin wire I can usually find a loop or hole to string it up for hanging. In addition, I use a piece of sprue carefully shaved and lightly stuck into an empty landing gear hole or empty propeller hole for stabilization with the free hand.
White glue works to temporally hold mounting sticks in various holes of an un-finished model. A little water and the glue softens up and cleans up nice.
It's ugly, but it works, most of the time.
Any other ideas out there?