The "crystals" used on quilts are glue-backed and need to be put on with a hot iron thingy. Sorry for the technical jargon. In my opinion, they really do enhance a quilt - in moderation. I have seen some show quilts that look like Porter Waggoner on Saturday night.
This is a detail from a first place winner at Road2CA. It is my daughter's and I helped by putting all the crystals on the quilt. It's not hard to do, just tedious and nitpicky.