Depends on what the show is offering but locally M & M, best turned out, best condition, best mare/gelding (whichever he or she is), not sure what else as I used to in hand with a 16.2 so the opposite end of the scale.
I know m&m is not plaited, what about best turned out? I am one of the odd few that enjoys plaiting, so want to go into classes where that can be done.
You could also (if pony suitable, and backed), find a mini jockey get yourself a matching outfit and do lead rein classes, and fun classes eg handsomest mare/gelding etc.