Since is my "collection" is so small at the moment, I don't have any special displays yet! Guinea fowl's skull is currently just sitting, but I do plan on putting it into a nice small display case of some sort. Haven't mounted any full skeletons either, only the few skulls/bones I have--would love to somehow put together a full mounted chicken skeleton eventually, afaik preassembled ones are pretty pricey from scientific suppliers.
At hobby lobby, I've seen the old-fashioned "dome"/cylindrical type glass display cases with wooden bottom. With some mounting and added decor inside, I've thought those may look nice as a display for a small skull like mine (or a very very small skeleton, like a rodent or chick). SkullsUnlimited website may sell cases? I haven't checked their selection.