Hobbies: Tag a bag
Clip one of these homemade tags to a backpack or lunchbox, and there will never be confusion about whose is whose.
Start with a metal rim key tag. Remove the ring, paint the tag, and let it dry. Decorate it with stickers or glued-on drawings or cutouts. Brush on a coat of decoupage medium (such as Mod Podge) and let it dry before replacing the key ring.