Yes, it's nerve-wracking to feel scrutinized by an interviewer, and a natural response is to want to measure up. But the wiser goal is to focus on learning whether you're a mutual match—emphasis on mutual. Think of it like dating: If you approached every date determined to make your date fall for you, you'd miss important cues about whether or not you were right for each other.
This means being honest about your strengths and weaknesses and giving the hiring manager a glimpse of the real you, so she can make an informed decision about how well you'd do in the job. It also means interviewing the interviewer, asking questions to figure out things like: Is the work well aligned with your strengths—your real ones, not the ones you puffed up in your cover letter? Is the environment one you'll thrive in or one that will drive you over the edge? Is the manager someone you'd want to work with? Or is she flaky and disorganized? An unreasonable tyrant? A wimp who can't get things done?
If you get offered and accept the job, you're going to be doing this work with these people, all day, every day. Your goal is to find out if you can do it well and happily—not to get the job at all costs.
Alison Green is chief of staff for a medium-sized nonprofit, where she oversees day-to-day management of the staff, as well as hiring, firing, and staff development. She is working with the Management Center to coauthor a book on nonprofit management. Her writings have been published in the Washington Post, the New York Times, Maxim, and dozens of other newspapers. She blogs at Ask a Manager.