A few years ago some unnamed marketing genius at the Walt Disney Company hatched the idea of pin trading: You get a lanyard and purchase little enamel pins depicting characters and attractions and other Disney-esque faff (there are roughly nine bazillion different designs). Then you can offer to trade pins with other guests you see wearing the lanyards, plus many employees wear them and are required to trade with you if you ask. It’s a hugely popular pastime, and there are pins for pretty much any Disney property you care to name.
Many of the pins are offered in themed sets, such as the much-sought-after princess mystery pins, the “pumpkin” villains from their 2015 Halloween collection, and the character silhouettes used in this neat project by Craftster “maleficent.” She made personalized boutonnieres for each of the groomsmen in her wedding, and the result is rather elegant.
There are lots of spooky sets which could be put to similar purposes–the Haunted Mansion alone has at least four (1, 2, 3, 4)–and then there are Nightmare Before Christmas, villains, Tower of Terror, and on and on and on. (It looks like Universal has also gotten into the pin-trading action: There are lots of Harry Potter-themed sets, like the Hogwarts crests.)
It’s apparently fairly popular to turn the pins into necklaces as well, so you could make a matching set for the bridesmaids.
Even if you don’t have any bridesmaids or groomsmen to attach these to, the pins would make lovely brooches or lapel pins to give as gifts.