Would you be able to get the teacher out of the class for a bit....maybe like recess time??? You could have the students put their thumb print using different colors of fabric paint on the bag and then with a permanent pen write their name underneath. I drew a big heart and printed the teacher's name and then the students all added their thumb print and name. The teachers loved it. Did it for all the teachers in the school. Was a hit. Another idea we used was finding a parent who was good at drawing and that parent drew a picture of the teacher (hard to explain how it was drawn except it looked like the teacher's face) with a permanent pen and her name under it. The teachers also liked those bags, too.