A gift certificate at a local Office Supply store would be most welcome, I am sure. Teachers ALWAYS need extra supplies for their classes and the money has to come from somewhere, usually their own pockets.

Or a gift certificate for two at a good resturant.

Say 'thank you' or otherwise, when there is a reasonable chance to express appreciation for their effort, do so.

Other than that, if you want to get them something they would like or could use or something like that just ask them. Express what your feeling is, and that you would like to give them something and that you need and value their input. Also make sure to mention the budgetary constraints if any will apply.

go out of your way to talk to the teacher in question and ask them because different people have different needs and might be most appreciative of different things on an individual basis (just like their students or any other people for that matter)

I don't do anything for teacher appreciation week. Our PTA does something & it's so close to the end of the school year I wait & put it all on a nicer end of the year gift.

For the teachers and crossing guards, I always give gift certificates for dinner. Also I have the children hand write a personal note of thanks.
Susie

One of the nicest things that a parent ever did for me was to write a personal note of thanks at the end of the year for all the things that I had done for her son. She sent a copy of the note to my principal and to the school board. (I still have the letter!)

Locally, our teacher appreciation is a week long. Our PTA is doing a breakfast, giving little tokens, having the kids create a journal/memory book for their homeroom teachers. We (the PTA) is doing something every day that week. One of the plans is to have volunteers available to watch the kids at lunch so the teachers can eat away from the kids.

As a teacher, I can tell you that there are several things that I appreciate from parents. First of all, know that Teacher Appreciation Week is a great idea but not all teachers are able to participate in the breakfasts/lunches! (I teach an afternoon Kindergarten class so with my teaching schedule, I miss lunch because my lunch break is at 10:00 a.m. and I miss breakfast because I team-teach at that time!)
1. Letter: Writing a letter to the principal and cc-ing it to the School Board/Superintendent and the teacher is a fabulous "gift" as it shows the parents' appreciation and effort, and makes a BIG impression on the administration.
2. Gift Certificate: Teachers are always appreciative of gift certificates to any office supply store, Target store, or crafts store. If there is a teacher supply store nearby, this is another great place to get a gift card. As a teacher, whenever I get a gc from a child, when I purchase something from that particular vendor, I always tell the entire class, "Oh, and a special thank you to so-and-so who helped pay for such-and-such today for our art project" or whatever. Grocery store gift certificates are also great for primary grade teachers (if the teacher does any cooking type activities). Book store gc are great, too.
3. Personalized: If you know the teacher well, and you know that he/she likes to get a cup of coffee at Starbucks, then a gc to Starbucks would be a nice personalized gift. Or, if the teacher likes fresh flowers, a single rose in a hand-decorated (by your child) vase such as a pretty water bottle would be wonderful. One of my personal favorites at the Christmas holiday is to receive homemade baked goods. Little things like this are always greatly appreciated.
Last year, one of my students' dads was a chef and he made the BEST cookies. So, I would get these wonderful cookies for different occasions and I just loved it! Amelia would make me a handmade card and dad would bake the cookies, mom would wrap them in cellophane with a little bow and I'd be in heaven! It was just one of the nicest gifts I could ever get. (my hubby, who is a teacher too, would ask, "Did you get more of Amelia's cookies?")

First find out if giving gifts is permissable in your school system.
Many discourage this, since many children can't afford to compete in that gift-giving game.

However , if it is permissable, I would suggest a gift card to Barnes and Noble or Starbucks.

After all, how many scented candles , perfume, jewelry or other similar things can a poor teacher use !