Summarize the following:
These nonverbal cues can show the other person that you’re fully engaged in what he is saying, and in agreement. Try nodding three times to show that you’re really absorbing what he is saying. When it comes to smiling, make sure it reaches your eyes! If you turn up the corners of your mouth but your eyes remain neutral, you could come off as fake and insincere. Don’t be obvious, but try to casually match her body language and facial expression. By doing this, you’ll help the other person feel comfortable toward you. This mirroring technique has even been shown to increase a person's good will toward the person mirroring her. If she's leaning on a wall, lean on the wall. If she has crossed her arms, cross your arms. It’s an effortless technique that can pay off big time. Even if you’re in a formal setting, if he has clearly said something that was intended to illicit a laugh, laugh! Show him that you have a sense of humor, and you’re listening to what he is saying. If you’re in a tense or nerve-wracking situation, laughter is a great way to help you loosen up and lighten the mood. Avoid laughing out of nerves or because you have nothing to say. Random, unprompted laughter may make you look uncomfortable and nervous.

Summary:
Nod and smile when appropriate. Mirror the person you’re speaking with. Laugh genuinely.