Personally I hate the Halloween Costume thingy but my wife loves doing it so I am in a "Yes Dear" mode with the best smile I can manufacture. This is at our Club every year and I did once see a couple come with no costume, nude saying they were streakers. It looked pretty dumb in my opinion.
We've not partaken in a Club/Resort Halloween Costume Party but we have attended a couple of costume theme parties; Mardi Gras! We bought masks. My wife did up her hair with feathers, wore a feather boa and some body glitter. I wore the mask, a hat, some beads, which I gave away quite quickly to all the women that were showing their boobs! hahahahaha
They were quite fun but in all honesty, the "costumes" didn't last long, nor did the masks, hats or beads. Within an hour or so, everyone was naked. My wife still had her feathers in her hair and the glitter, which I had all over my body... and face! :DDDDD
When we were in our rookie year at the Club we got dusted with glitter at some Dance party by some lucky go happy person. We did not know to shower off outside at the Bathhouse or at the Pool we showered off in our Camper. For the next year we were finding and cleaning glitter up in the Camper. Someone breaks glitter out after that you will find us at the opposite end of wherever.
At a nude Halloween party I've seen body paint, masks, capes, hats, etc... People can be pretty creative
The best part of Halloween is to really elaborate the outfits the fact of being nudist does not interfere with the possibility of enjoying certain type of celebrations that requires clothing or accessories.