As the yoof of today's messes have all the mod cons/boys toys they want, you need to think out of the box.
Best one I remember (can't think from where) was a year of a reserved parking slot outside the front of the Mess. It was good to see "Fg Off Bloggs" written on a blue sign next to OC 123 Sqn and OC Trivia Wg .....
.....or a day's slightly dodgy "Extreme Activity". Last year someone bought the senior daughter a day out which involved rolling down a hill in a water-filled sphere...... my how we laughed at her shrieks of terror....