N.M.
Homemade goodies like fudge and cookies would be good, but not everyone has time to make them. I know teachers get lots of candles, lotions, and knicknacks, so probably stay away from those. Gift cards are a great idea, especially for Starbucks because they will use it as a treat for themselves (rather than for the class, like a gift card to Staples, even though those are useful). Don't worry about whether or not they like Starbucks. I've received Starbucks gift cards before and I don't drink coffee, but I have never had a problem finding something to do with the gift cards.