When selecting the item, many have obvious places for the names to be added.
Some have space for a short message too. Its a good idea to make a few notes before ordering, and have a list and notes ready when you order.
However from experience, many people request far more than will fit comfortably.
Keep messages short and sweet for best results. "Hopkins Christmas" - "The Culverwell's" for example.
We always try and include the year, as the years go by it great to add to your collection and amazing after a few years trying to remember how many Christmases you have been hanging the decoration for!