I always did, usually separate from my last tab (plus customary tip) of the year. Usually I would send or hand-deliver a greeting card with a note of thanks and a pretty substantial bonus tip. One year I made an elaborate presentation of it, with a little stocking and candies and crisp cash rather than a check.
However, the year before last, he didn’t think to mention the Christmas tip until my first appointment of the new year, late in January (“Did I ever thank you for the check?”), and last year there was no acknowledgment at all, not a phone call or a note or a belated word or anything. He cashed the check fast enough, though.
So—no bonus tip this year.
I’ve been with this person for many years, and we have a warm relationship. I also try to remember not to antagonize someone who’s { holding the scalpel | drilling my teeth | cutting or coloring my hair | engaging in any other business that’s risky for me }. But I’m the customer. I gave him a gift. He didn’t value it enough to say a single word to me. I have other uses for the money.