Every morning, my students greet me with one of these ways to say "Hello!" It automatically puts them in a good mood and a huge smile lights up their beautiful faces. I have this right outside my door.
Then, on the opposite side- we have these fun ways to say Goodbye. At the end of the day, the Line-Up Leader gets to choose which way we will say good bye to each other. Once again, my students always leave with a smile on their faces! (Plus these even rhyme!)