I tip my hairdresser every time I'm there, so no extra tip at Christmas.
Other than that, I tip most everyone else. Letter carrier, UPS, garbage guy and water delivery guy. But, I run a business out of my home so at Christmas, I like to compensate for the little bit of extras they do during the year. Not a lot, but they get a gift card to the big mall by us.
Our letter carrier is always dragging boxes up to the door, as does the UPS guy. One year, we were on vacation and a load of boxes came. The neighbors were on the lookout for them but the UPS man carried them over our locked gate, around to the back door, tucking them under the overhang. It was days before the neighbors spotted them out there. Too me, that's above and beyond and I don't mind tipping. The water man will always help me get the water into the house if I'm home -- that way, it doesn't freeze outside during the winter. Even the garbage man has been known to stop back at the end of the day to pick up the garbage we have that's above our quote. Not always, but if he has room in the truck and we have a lot of extra, he does.
If we have a problem, I don't tip. When we had the daily paper delivered, the guidelines were that it had to be delivered at the front door. If we didn't wake up to a loud bang in the morning from his hitting the house with the paper, he'd somehow manage to knock over our flower pots. One time, he managed to hit the nozzle for the hose and turned it on. As if that isn't enough, he would run off the driveway, in his hurry to deliver the paper and we'd have ruts in the lawn. So, no tip for him -- at we eventually got to the point where we asked that our paper be left at the end of the driveway.