The holidays are a time to let everyone in your life know how much you appreciate them -- teachers included. Getty Images

The holiday season is a time for giving, and there are few people more selfless than the nation's 3.5 million teachers. Show your children's instructors how much you care with a Christmas gift that's both thoughtful and useful. Skip the apple and get them something they'll truly appreciate. Here are a few of the best ideas from around the Web:

Food. Hey, teachers have got to eat, too. Corral your kids in the kitchen and whip up some baked goods they can proudly deliver at school the next day. This cinnamon roll recipe from the Pioneer Woman makes eight pans of doughy deliciousness, allowing you to widen the gift list. Why not take trays of rolls to the bus driver, librarian and principal, too?

A framed letter. Need something cheap, last-minute and heartwarming? Have your children use their best penmanship to write letters describing how much they love being in school and what their favorite things about their teachers are. Let your kids sign and date the paper, then stick it in an inexpensive frame to create a present the instructors will treasure for years.

Gift cards. Everyone loves gift cards, and teachers are no exception. They can use gift cards to stock up their classrooms or treat themselves, depending on the store you select. Good options include Starbucks, Target, Amazon, Michael's, bookstores and local movie theaters.

Chocolate. Yes, this is a separate category from food. Teaching is stressful, and everyone can use an emergency stash of sweets. Skip to My Lou designed an adorable printable to dress up Hershey bars.

A chalkboard mug. This gift can be cute and customizable if you're willing to do a little DIY. These directions from Wit and Whistle suggest you simply get a porcelain mug, wrap tape around the lip and paint with porcelain chalkboard paint. Carefully remove the tape and let dry for a day. Then bake the mug at 300 degrees for about a half-hour, or as the paint package directs. Write a sweet message with chalk and fill with instant coffee packets before you give to your favorite teacher.

Top-of-the-line school supplies. Due to tight school budgets, teachers often rely on the same worn-out resources year after year. Freshen up the supply closet with items they can't afford, like a new 24-pack of Sharpies or a color printer.

An email. ChicagoNow came up with the easiest gift ever -- a compliment. Simply compose an email specifically writing what you love about a certain instructor's efforts or classroom and send it to the principal and county superintendent. The praise will mean more than you know.