I've never give cards out in ten years. That's not to say I've never thought about it.
After working all day, collecting a few nights a week I decided I couldn't be arsed writing 8 million cards out.
So they just get a merry crimbo off me and 5 mins chit chat at the door. I always ask any kids what father crimbo is bringing them and all that stuff (gets them even more excited).
Anyway I usually get a decent amount of tips, chocolates and cards.