Most of my stencils have holes in them. I use something called a "hinged snap ring" - I found a picture of what I mean. If you go to this website:
http://www.hudson4supplies.com/en.us/product-8120
I open the ring and put x number of stencils on the ring. Then I open the ring and put it over a hanger and then close it. I have about 5 rings on the hanger, each one with about 14 or 15 stencils on each ring. I try to group the stencils into groups that are alike to make it easier to find what I want when I want it.
I buy my snap rings at Lowes and they are NOT expensive!
I hope this helps some.
PS I also use this technique for taming my quilting rulers - the ones I don't use all the time but own for a specific project!