Holiday Mixer Activity - a Holiday Party Idea Who Stole the Holiday Cheer? Holiday Mixer Activity Is your annual holiday party all that it could be? Do you want it to be more than just great food and music? Make this year’s party fun and memorable with a holiday mixer activity. This downloadable package comes complete with clear instructions on how to implement the activity and professionally designed graphics for you to use. This holiday activity is sure to get your guests talking during AND after the party.