Some of my favorites have been a handpainted ceramic apple I keep matches in it, it has a lid and is so obviously painted by a child), a handpainted flowerpot that the child included my favorite bird on it (blue heron) came with a little plant that didn't make it but I still have the flowerpot on my kitchen windowsill holding odds and ends,a Staples gift card (not for too much but I could get a few things I needed for the classroom), a little jar (Mason jar type) with sewing things in it with a padded lid with sewing themed fabric - like a mini sewing kit that I could keep at school..
One thing I really don't need is another teacher mug although I've had a few that I've loved. And the person that posted about a note of appreciation - that would mean the world to me (have gotten a few over the years and if a copy went to my administrator, I wouldn't mind that at all.
A totebag would be appreciated, I think, if the person doesn't sew him or herself...
Hope this helps!