Well, first off - nothing that might be pilfered. Lanterns and jewelry would look smashing, but I can't be responsible for them and I don't think you want to see someone walk off with your goods. But if anyone has spare room in their vehicle for a small wooden crate, a few yeards of burlap, or even a ships wheel that could be leaned against the wall - that sort of stuff. I know that for the most part it's unlikely that anyone will have such large ticket items lying around and the means to easily transport them, but I figured it's worth throwing out there just the same.
I've not even seen a picture of the room, so I'm flying blind. But I certainly have a large assortment of pirate flags I'll bring, an old smashed up barrel, some small furniture to DJ from, some tattered fabric I can drape over anything unsightly, etc.