Say, as a fantasy, if you had (or have, for those lucky ones who does ;p) a slave, then would you have her dress up, or rather, cosplay for you? If so, then as what? The possibilities are quite a few; you could have her dress up into a maid-costume, a school-girl unifrom, a china dress, a nurse wear and so on.. Or perhaps go a little futher and have her dress up as something fantasy-themed, like an elf, a warrior, an amazon a cat-girl, etc...
At least, I imagine that having your slave/submissive doing something like that and then make a play of it all or something like that, like; your slave/submissive dresses up as a warrior/warrioress (and so do you, of course), then you play two warriors who meet as enemies on the battfield and "fight" (with plastic swords or something) with each others until you "defeat" your submissive and then according to the rules of war, claims your price...
Well, everyone? What would you like your submissive to dress up as... or even, wish that your master/mistress made you dress up as, if the idea of "dressing up" haven't entered his/her mind?