The Secret of Santa's Island is a great book that I was introduced to just last week. It is about a boy who receives the ultimate gift from Santa--all because he said "thank you".
The story ends with Santa giving Sam a snow globe with this inscription on it:
"Thankfulness is the secret to happiness."
I gave my kiddos a paper plate with the instructions to draw/color/write something(s) for which they are thankful. We added a trapezoid to make the bottom piece, with the quote from Santa.