One of the first things I was told to do to prepare for the first day of school, was create procedures for everything. There are some teachers who have procedures for everything, it is how they have order in a chaotic classroom full of teenagers.
I do not have too many of these, just because I find that they are more of a headache to enforce, but I do have one that my students notice when I do not do. It is how I dismiss them from class. I do not allow students to line up at the door way because it makes me feel crowded, but I do have one "magic" phrase that dismisses them:
Bye! Have a great day! Make good decisions!
It started out as a joke, because the students would lovingly tease each other and I would tell them to be nice to each other. It then evolved to telling them that they needed to make good decisions, and being nice to one another is a good decision.
I received a few responses, two my favorites being "What's a good decision?" and "You make good decisions Ms. Evans". Whenever I forgot to say it, my students would tell me "Bye Ms. Evans! Have a good day! Make good decisions!" If I am absent one day, my students will tell me the next time they see me that they forgot to make good decisions the previous day, because I was not there to remind them to make good decisions.