At Bunko everyone was having a problem remember which plastic cup was theirs so I made cup sleeves for everyone. I have an embroidery machine so embroidered everyone's name on them but you could use different print fabrics to instead.
Attached is picture of a sleeve I made to use when I'm in my singing group and don't want to lose my Starbucks.
Send me a personal email if you're interested and I'll give you the directions, they are really easy.