As the daughter of a Teacher/Principle I have a little insight into teacher gifts. I try to stick with consumable items. (I have ton's of mugs that I don't know what to do with and I don't have 25 kids giving me various gifts throughout the year.)
Thanks to the Internet there is lots of information on what teachers actually want/need. The number one thing mentioned was not gift cards, or bottles of wine, or even cash... It was hand-written notes from kids or parents about what the teacher had meant to the student. Nearly every teacher mentioned that these notes and letters were the thing that they kept, looked at again and again years later, the things that really meant something to them.
So however you decide to show your appreciation make sure your child writes a note sometime during the school year.
Next to a handwritten note, a gift card to a favorite place, a coffee shop near the school or a store where the teacher may spend their own money on classroom stuff is always welcome. Some teachers warned us to be thoughtful where the gift cards were for, as they may not get used. For example, buying a gift card for a mani/pedi at a place that's inconvenient or for a store that the teacher maybe can't afford (like a $10 card for a high end department store where nothing costs $10).
Teachers also mentioned a lot that they didn't care how much you spend. It's easy to do nothing because you can't afford an amount that is truly representative of your appreciation. Get over yourself and just do something! (Yes I'm talking to me.)
I used a great free printable cards from Chicabug to jazz it up. I downloaded the file and printed it. I didn't have card stock so I printed on regular copy paper. And folded it carefully in half.
You will notice that the color of my card is perfect for Valentine's Day and isn't one of the options at Chicabug. I achieved that "custom" color by using an ink cartridge that was low on ink and needing replacement. (Yep, being a cheapskate and lazy can have it's rewards.)
Once again this week I grabbed my old scrapbooking supplies, and used my Crop-A-Dial to add grommets to the corners.
tape secured the gift card to the paper.
Then my daughter signed the bottom. Cute, usable, and less effort than the Valentine's we made for classmates.