Each time a class comes to the gym, I make a quick check of everyone's feet. If everybody in the class has on their tennis shoes - they get a sticker on the chart. When their class receives 5 stickers, they get a "Fun Day". This is a day where I set up various stations that they can rotate to throughout the class period. At the very beginning of the year, I let the students know how important it is to encourage their classmates to wear tennis shoes-instead of getting angry with those who forget. If a student forgets one time...it usually doesn't happen again!