This idea came from Mrs. Maddy, a teacher in my county. By my door I have a stand with a binder of all the Recorder Karate songs. Each song is copied onto a piece of cardstock that reflects the belt color. At the end of our lesson students line up and I listen to students play for belts until their teacher arrives.
In a box next to the door I have all of the yarn and beads that I use for recorder karate. I select a responsible student to cut belts so that I can focus on listening to students perform.