For a good number of years now, we have been displaying our Christmas cards on the back of our front door. That way when you leave the house, you can't help but see them. We get lots of comments about all the lighthouse Christmas cards and the non-lighthouse Christmas cards are mixed in. Usually more lighthouse cards than not. We use to display them on the wall above the fireplace mantel, but after we painted several years ago, we decided no more and moved them to the door.
After Christmas, the cards come down and go in a shoebox until the following year. Those that are not photographs of lights, I use for workshops with the kids and we make puzzles out of them. So if you don't know what to do with those cards after Christmas, you can always send them my way.