Actress Anya Taylor-Joy, the star of Netflix's mega-hit The Queen's Gambit, did not know how to play chess before filming began. But once Taylor-Joy took on the character of Beth Harmon, her attitude, expressions, and mannerisms gave viewers the impression that she really was a chess champion.

Taylor-Joy leveraged a technique available to anyone: acting

I've often said that great public speakers are made, not born. Speaking is a skill that can improve with practice. Not just any kind of practice, but the same strategy that actors use to look the part. 

Start with positive self-talk

Ryan Serhant was making just $9,000 a year as a real estate agent when Bravo began holding auditions for successful agents to appear in a new show. Serhant answered the casting call along with thousands of other reality-star hopefuls.

He not only won the co-starring role for Million Dollar Listing New York, but his firm broke $1 billion in sales just a decade after he started in real estate.

I recently interviewed Serhant about his new book, Big Money Energy. In it, he tells the story of nearly talking himself out the audition before it began. While he was waiting in the lobby for his interview, insecurities filled his head:

Who am I kidding? I'm not a top broker. I've only been in real estate for a year and a half.

Do you recognize these thoughts? You might think similar things to yourself right before a presentation. If you do, your body language and vocal delivery will give away your insecurity. 

Serhant's thoughts almost got the best of him, too. But something happened that turned him around. As he walked toward the interview room, he saw other brokers waiting their turn. He thought to himself that someone was going to get the spot. Why not him? 

Serhant's entire demeanor changed. He walked into the room acting like he was New York City's top agent. His posture, energy, and voice were strong, confident, and resonant. For a short time, he acted like the best broker in the world. And it worked.

Serhant's advice: "Fill your mind with positive thoughts for at least 10 seconds before meeting anyone. If your head is in a good place, you'll exude positivity and confidence."

My wife, Vanessa, and I have been coaching CEOs and executives for 15 years on communication and presentation skills. Vanessa has a background in psychology, which she puts to use when offering feedback on a speaker's performance.

She always begins with a person's strengths. Always. Speakers who express disappointment in their own performance suddenly perk up. They stand taller, hold their heads higher, and put a smile on their face. They try their presentation again. Their gestures are grander and they have a stronger, more confident vocal tone.  

What changed from one practice session to the next one a few minutes later? The speakers filled their minds with positive thoughts. But you won't always have a cheerleader by your side, so it's up to you to spotlight your strengths. 

Borrow someone else's style (temporarily)

When I started my career as a television anchor, I didn't know how an "anchor" is supposed to look and sound. So I watched hours of top-rated broadcast journalists. I tried to mimic their smooth delivery and the variation in their vocal inflections. As I became more comfortable and confident, my own style began to emerge.

Watch your favorite TED speakers. When you practice your next presentation, visualize yourself speaking with the same confidence, delivery, and even gestures. It will make a big difference in your real performance. And don't worry. You'll eventually develop your own style. 

There's a subtle but important distinction between acting like someone who's confident and "faking it until you make it." Faking it implies that you're pretending to be someone that you're not. That can lead to embellishing credentials or exaggerating your skills. If you feel like a fraud, it'll show.

Instead, I'm suggesting that you act like the speaker you want to become. You'll get a better response from your audience, which, in turn, will build your confidence. Eventually, you won't be acting. It'll be all you.