Step 1: Determine what you really want.

Say you’re arguing with your sister about caring for your elderly parents. You feel as though you’re shouldering more than your fair share. In the heat of the moment, you can easily become angry and flustered, and that’s not the time to negotiate. Instead, stop, acknowledge that you want to work things out, and “suggest an alternate time for discussion,” says Rick Brinkman, a communication expert and a naturopathic physician in Portland, Oregon, and a coauthor of Dealing With People You Can't Stand: How to Bring Out the Best in People at Their Worst ($17, amazon.com).

What’s most important is thinking about your ideal outcome―in this case, a more equitable distribution of responsibility. Writing down your feelings or talking through them with a friend may help give clarity to your thoughts, says Elinor Robin, Ph.D., a mediator certified by the Florida Supreme Court, a mental-health counselor, and a mediation trainer.

What could trip you up: Letting your emotions get the best of you. “When people get emotional, they become accusatory and start blaming,” says G. Richard Shell, a professor of legal studies and business ethics and management at the Wharton School of Business of the University of Pennsylvania and a coauthor of The Art of Woo: Using Strategic Persuasion to Sell Your Ideas ($16, amazon.com). Resist this by taking a deep breath and reminding yourself of your real goal. (Yelling at your sister, as satisfying as that may be, is―guaranteed―not it.)