In this contest, keen observation wins the game.
Divide into two teams (A and B). A-team members leave the room and must switch various items of clothing or accessories with one another, then return to the game room.
B-team members have five minutes to try to guess all of the switches that have been made. Add up how many items B-team members guessed correctly. Then let the B team have a turn to switch and let the A team eye-witness what's different.
The team to get the most correct answers in five minutes wins.