

Give each guest a small piece of paper with a number on it. Then put a copy of each number into a hat or basket or other suitable container.
The hostess or bride-to-be picks one of the numbers from the hat or basket and the guest with the corresponding number wins a prize.
The prize of course need only be a token gift but if you would like to give a larger prize then this, if appropriate, could be the bridal shower centerpiece.