I'd try to go with something classic/classy that they can use elsewhere. Maybe just the first initial of their first name would suffice? Amazon has these for $17. They're pretty cute.

http://www.amazon.com/Mud-Pie-Canvas-Monogram-Initial/dp/B00380X3S0/ref=sr_1_1?ie=UTF8&qid=1368588301&sr=8-1&keywords=monogrammed+tote