Some of the stranger things that I carried the following as a coach and still do as a cheer mom...
A large empty ziploc bag (which can be filled with ice in an emergency.) Sometimes it is easier to just hit snack bar than to wall across an arena for first aid.)
A small glue gun to fix broken bows an elastics . I have used this numerous times!
Pads/tampons, extra socks, disposable nail polish wipes, extra shoelaces, safety pins, highlighter, sharpie, copy of schedule, small flashlight, Mr Clean eraser for dirty sneakers, extra bow, *phone list of athetes AND parents
Tums, advil, tylenol, liquid bandaid, bacitracin, bandaids, wraps, sugar ( for low blood sugar), granola bars,visine, insect bite cream (which also works for sunburns)
morphie, chagers for both apple products and reg cord
I aso keep a bag of old sneakers in the car, just in case someone forgot them.