Gift ideas needed for daycare istants?

My daughter attends a daycare which has approx 35 high school students as "student teachers". They're learning a technical trade in childcare, obviously. :) Anyone have a good idea on how to thank these teachers at the holiday time? The primary teachers (4) I have purchased rather nice gl ornaments but am totally stumped as to the 35 remaining. I want to show our appreciation but don't want to break the bank. :) Thanks in advance!