I have limited display space but I have a little wall unit that has thimbles people have given me -- I don't actually really collect them. I keep my quilt pins on a bulletin board. I have a lot of different funky textile art things I've found at thrift stores, from a cool 60s pillbox hat, to cute 1970s girl scout?? type art piece on 70s calicos with a felt rainbow, to all sorts of other treasures.
The old type of large glass canning jars with the lids and the metal clamps are great for storing things like thread, you can see in clearly while keeping the dust and things out of it.