Learn to close doors gently enough that bitterness does not follow you through the next one.

How you close something determines what you carry out of it. A door slammed on the way out tends to keep making noise for years, coloring the next thing and the person you are inside it. Closing carefully is not for their sake so much as for what you take with you.

When you end something, say what is true without adding the extra sentence you would enjoy saying. That restraint is what keeps the next chapter from starting with an argument you already left.