I often struggle with ideas of what to give to my kid's school teachers. Every few years I remember this simple idea: a decorative towel and hand soap. Two things that just about everyone can use. If you have a little bit of extra time to spare you can whip up an embellished towel with some of your fabric scraps. I use this tutorial.
And along with a gift to any teacher I have my child write a thoughtful note and/or draw a picture.