You have one in your life. Everyone does. Let's call her Emily. Emily is a good friend in some ways, but she has one big fault: She's a bailer. You have lunch plans; she's swamped at work. Dinner? She's exhausted. Sunday brunch? Book club? One excuse after another. You've finally had it. When you're ready to confront her, try the "praise sandwich" technique, says Bruce Weinstein, author of Life Principles: Feeling Good by Doing Good (Emmis Books, $18, www.amazon.com). "Starting by saying something both flattering and sincere — 'I really value our relationship' — will make her more receptive to your criticism," he says. Then tell her how her behavior upsets you. Make sure she understands that you're serious, but don’t issue an ultimatum, Weinstein advises: "It's implicit when you say, 'I hope we can work this out, because I enjoy going out with you.' You're saying, 'If we don't, I won't.'" Finish by affirming that you care and have faith that she can change.

If Emily cancels on you again, you could resign yourself to being phone friends. On the other hand, "she's not respecting you," says Weinstein, "and without mutual respect, it's difficult to have a meaningful relationship." In which case, maybe it's your turn to bail on Emily, for good.