I think ribbons from the 2nd set, rather than crown clips. Those come up a lot, it;s generally a matter of price that may make them prohibitive. I also didn't have too much trouble getting Taffeta's accessories, but I still don't have her ribbon and the only loose ribbon I have for a year 2 Princess actually came to me with a variant princess so belongs to her...I have genuinely resorted to trying to get that set MIB because getting all the accessories separately is a nightmare.
I am still missing, I think, a particular pink wand from the UK release but since I can't judge it from pictures, it's impossible to go after it on auctions...