Looking for a unique way to thank someone for their efforts?  Consider sending candy and/or other food items with a special greeting.  Here's a list of potential ideas to get you started:

Thank you for being a red hot volunteer! (send with Red hots candy)

You're a star in my galaxy! (Milky Way candy bar)

You're worth even more to me! (100 Grand candy bar)

When it comes to helping out, you're worth a mint! (Peppermints)

I'd be in knots without you. (Pretzels)

I'm nuts about you! (Peanuts)

You never snicker at my concerns; thanks for being such a great friend! (Snickers candy bar)

Here's a kiss and a hug for all you do! (Kiss and Hug)

You're the apple of my eye. (real Apple or apple-flavored Jolly Ranchers)

Bar none, you're the best! (Bar None candy)

Thanks for adding jo to my life! (Almond Joy candy bar)

For all you do, you deserve an extra pay day! (Pay Day candy bar)

That was a whopper of an idea . . . and what a great one it was! (Whoppers)

You've made a mound of difference.  (Mounds candy bar)

Thanks for going to bat for me! (Babe Ruth candy bar)

This place would be a zoo without you. (Animal crackers)

You're a lifesaver! (Lifesavers)

You add pop to my life. (Popcorn)

You're the best prize I could ever hope to win. (Cracker Jacks)

You're a star in my eyes.  (Starburst candy)

It's a real treat to work with you.  (any candy)

"Twix" you and me, you're the best.  (Twix candy bar)

You are more precious than gold. (gold-wrapped candy)

Thank you for staying fresh with your ideas. (Winterfresh gum)

Thank you for putting your heart into our organization.  (Candy hearts)

Feel free to modify the sayings to meet your needs.  Consider the last greeting, for example.  Instead, you could write, "Thank you for putting your heart into teaching our children!."