Do you have any personal etiquette rules you like to follow?

I’m talking about rules that aren’t necessarily dictated by Emily Post but that you made up or someone taught you that you tend to follow. For instance I don’t know if it is a true etiquette rule but when I am being treated to a meal I make sure my entree costs less than what the person footing the bill is ordering and I never order dessert unless my host does. Do you have any rules like these that you like to follow?