The biggest mistake we see in early rehearsals is that people move their bodies too much. They sway from side to side, or shift their weight from one leg to the other. People do this naturally when they’re nervous, but it’s distracting and makes the speaker seem weak. Simply getting a person to keep his or her lower body motionless can dramatically improve stage presence. There are some people who are able to walk around a stage during a presentation, and that’s fine if it comes naturally. But the vast majority are better off standing still and relying on hand gestures for emphasis.

Perhaps the most important physical act onstage is making eye contact. Find five or six friendly-looking people in different parts of the audience and look them in the eye as you speak. Think of them as friends you haven’t seen in a year, whom you’re bringing up to date on your work. That eye contact is incredibly powerful, and it will do more than anything else to help your talk land. Even if you don’t have time to prepare fully and have to read from a script, looking up and making eye contact will make a huge difference.

Another big hurdle for inexperienced speakers is nervousness—both in advance of the talk and while they’re onstage. People deal with this in different ways. Many speakers stay out in the audience until the moment they go on; this can work well, because keeping your mind engaged in the earlier speakers can distract you and limit nervousness. Amy Cuddy, a Harvard Business School professor who studies how certain body poses can affect power, utilized one of the more unusual preparation techniques I’ve seen. She recommends that people spend time before a talk striding around, standing tall, and extending their bodies; these poses make you feel more powerful. It’s what she did before going onstage, and she delivered a phenomenal talk. But I think the single best advice is simply to breathe deeply before you go onstage. It works.