The Elf on the Shelf is a popular holiday tradition that involves placing an elf toy in various locations throughout your home each day to observe the behavior of children. The elf is said to report any naughty behavior back to Santa each night and reward good behavior with small gifts. To do the Elf on the Shelf, you'll need to purchase or make an elf toy and then decide where you want to place it each day. You can also come up with creative ways to have your elf interact with the children in your home.