When my husband was a missionary, he and his companion took this picture to send home to their families for Christmas. I believe they took it at a Walmart.
Two years ago we took that same idea and took a picture at a Target. We probably should have picked an aisle that was less bare though!
If you need to take a family picture earlier than most stores have Christmas stuff (though seriously, that's getting to be less and less of a problem- Christmas stuff goes up with Halloween stuff now) hit the craft store. Some craft stores have Christmas stuff year round.