Make nooses out of leather string and hang them on the wall with robe hooks.
How many do you have? What about this?
You should be able to use a guitar wall-hanger. Here is one type, and they are generally less expensive when purchased as a set. https://www.amazon.com/AW-Guitar-Hanger-Holder-Display/dp/B074494N2T/ref=sr_1_46?keywords=guitar+hangers&qid=1568942195&sr=8-46 Most screw into drywall, so, if you don't own your house, you need to have permission to put holes in the wall. If you are handy and have some tools you can make your own as shown here: https://www.instructables.com/id/Guitar-wall-hanger/
I know you can buy specialty display hooks for guitars and they should work for your needs. You could also install wood shelves and lay them on them, either showing the face or lay them completely flat, showing the side.