L.C.
I never gave the teachers Christmas gifts, but at the end of each school year I would write a letter to the administration telling them all the good qualities of the teacher. (The year we had a dud, I just skipped the letter...)
I gave the teachers a copy and the administration would put the letter in their file.
The teachers really appreciated the letters! The Band Director at the middle school has 5 of my letters - all different - one for each year my children were in his class. He told me that when he has a particularly bad day, he pulls one out and reads it. It makes him feel better and helps him remember that he really is making a difference.
YMMV
LBC