As a teacher, I used to get some nice chocolates and things like that, and one year a got a bottle of champagne from a pupil I had helped a lot. This was brilliant!
Now I buy stylish but cheap little packets of Christmas biscuits from John Lewis for the TAs, with a hand-drawn label made by the kids, and usually give a bottle to teachers, or a decent plant that they could use in the classroom or take home. If they have really put themselves out for my child I might give champagne - for example one year the SENCO and ds1's form teacher (same person) bent over backwards to help him to get a statement of SEN, which made a big difference to us all, and I felt this had actually had had to go beyond the call of duty at some points. Hence I wanted to make a big gesture.
One year ds2 had a frankly incompetent, grumpy teacher who made no effort at all with him, or indeed his classmate who had cancer and got no support from her at all, and I blanked her that year. Not a single card or present out of this family. I still blank her when I see her! Cow!