If you’re managing people, don’t play favorites. Say Jim comes to you and asks for advice on how to handle a difficult co-worker, Ray. Encourage Jim to discuss the matter privately with Ray. If that doesn’t work, invite Jim and Ray to a meeting so that the three of you can hash it out together. That’s better than strategizing with Jim on how to handle Ray. You may wind up psychoanalyzing Ray or saying something that you wouldn’t say to his face. That will undermine your credibility when Ray finds out—and you can bet that he will.