Dream Co and costumes

So this has been bothering me for awhile...
Does Dream CO provide "costumes" for the dreamer or does the dreamer create (or mostly create) their own out of their heads.I feel some have to imagined because otherwise all dreams would have to start out with the dreamer naked... Clearly, Fi's prom dress would be an actual costume but how much would be imagined and how much would be provided. Particularily I am thinking about Fiona running out of socks and having to wear "devil socks."

I worry about this stuff because I work as a costumer at a theatre. I won't bore you with my speculations on the organization of Dream Co's costume department and stock...

There is a huge costume industry as part of DreamCo. I think there was a sentence about it in the DreamCo manual. But yeah, people build sets, make costumes, even do catering, just like Hollywood! (But less strange.)