The key, as in any relationship, is how you handle the anger. When what you say hurts, acknowledge the other person’s pain. Don’t pretend it doesn’t hurt or say it “shouldn’t” hurt—just show that you care. Eliminate the phrase “don’t take it personally” from your vocabulary—it’s insulting. Instead, offer to help fix the problem. But don’t pretend it isn’t a problem just to try to make somebody feel better. In the end, caring personally about people even as you challenge them will build the best relationships of your career.