One of the books I am reading is a novel called "Gone Tomorrow" by Lee Child.
There is a great line in chapter 43. "Before you criticize someone, you should walk a mile in his shoes. Then when you start criticizing him, you're a mile away and he's got to run after you in his socks."
I think that is a great way to remember to keep my mouth shut. It doesn't make me look any better if I have something rank to say about someone else. It may even make me look foolish. Or jealous. Or immature.
So I try very diligently to speak less and listen more.