I had a bunch of pewter buttons I bought from a boutique going out of business and wanted to display them. I digitized a button card. The buttons were heavy and had shanks, so I digitized a buttonhole for the shank and attached them on the back with a pipe cleaner - this way they can be easily removed.
If you google quilt for pin collection you will see lots of ideas. My favorite is the dress making dummy covered with brooches.