I am doing Happy New Year cards this year instead of December "holiday" ones. Someone in another thread last year pointed out that if you shoot for Thanksgiving or New Years instead of Christmas, your cards/gifts don't get lost in a sea of others.
Now to answer your ACTUAL question, Tess.

I do lots of short one-off jobs, so for most clients, I just send a card with a personal handwritten note. Two regular clients will get either Fairytale Brownies (seems to be a popular choice around here!) or a selection from
The Toffee House. But I write for the food page in my community newspaper also, so the editor there will get a bunch of homemade goodies. He's a fellow recipe-collector-experimenter, so it's appropriate.