It’s difficult for many speakers to remember exactly what they want to say during a presentation and to deliver their message with the right emotional impact. When you stand in front of an audience, people aren’t just listening to you. They are also watching you. Your body language, in particular your hand motions, also communicate your intention. To make the right impression, consider these suggestions summarized by Brian Lee at Lifehack.

Lee reports that 93% of communication occurs through non-verbal signals. The rest of the communication takes place through what you say. Lee draws his data from The Definitive Book of Body Language authored by Allen Pease and Barbara Pease.

By now, we’re all familiar with President Trump’s habit of signaling OK with his right hand during speeches. Experts say this hand motion shows authority but not aggressiveness. Audiences often prefer seeing the OK signal as opposed to other motions such as finger pointing. For many of us, finger pointing brings back memories of a teacher or parent accusing us of wrongdoing. As a speaker, you don’t want to put your audience members on the defensive. They may form a negative opinion of you or stop listening if you single them out with finger pointing. The same holds true for putting your hands on your hips. Don’t do it.

During a speech designed to convince audience members to agree with what you are saying, try out the “side-palm.” Hold one hand slightly up from the podium, open, and in the position you would use to shake hands. President Obama used this technique frequently. Lee observes that this strategy of reaching out to the audience may put them in a positive frame of mind.

You should also avoid showing nervousness with your hands when you’re in front of an audience. If you typically pick at your fingers or wring your hands, try to change that behavior. Videotape yourself giving a presentation and watch your hands. It’s easier said than done when it comes to changing your style of physical communication, but practice makes perfect.