When I owned a Child care Center some of the most memorable gifts were supplies. A homemade play dough, wood blocks cut up, sanded, and painted. One of my parents had a body shop so they borrowed some outdoor toys, they were metal fireturucks, a batmobile, and benches, they sand blasted them, well I think they used baking soda instead of sand, anyway they stripped the toys and repainted them. They used heavy duty paint so the toys are still looking good 10 years later. One of my parents cleaned their classes carpet, one made new curtains. It can be anything.
I had my best friend make bead necklaces for K's Head Start Teachers. I wanted them to have something personal they could take with them. They wore totally different color groups. One wore oranges, greens, and browns and the other wore pink, reds, and blues. I picked out the beads from my friends selections and paid her about $10. for each necklace. She sells her jewelry for a bit more but was willing to give me a deal. You can buy things for crafts similar to this at Hobby Lobby, especially when the jewelry making supplies are on half price. Several things are 50% off this week in that dept.
If you want to give them something they will count as their own you can always give books and write their name in the front from your family. When I left my center I took my things with me and still have them. You caould make them craft aprons with lots of pockets. Skinny slots for crayons, heavy (double or triple thickness) pockets for scissors, etc....
I think teachers work very hard and I always appreciate stories of good ones, there are always so many posts about moms not liking their kids care givers and it always makes me sad. Thank you for sharing that there are good ones out there.