Every year I teach a class of elite business professionals who are enrolled in an executive education program at Harvard University. They are required to participate in group and individual presentations to graduate. After their presentations are complete, I recommended that each student practice their final presentations a minimum of ten times from start to finish. The ones who do stand out. 

I learned this technique from studying and interviewing the TED speakers whose talks went viral. For example, brain researcher, Dr. Jill Bolte-Taylor, told me she rehearsed her TED Talk not once or twice, or even ten times. She practiced it 200 times. Her "Stroke of Insight" has been viewed more than 22 million times and is ranked as one of the most popular TED talks of all time. 

Dr. Jill's example is extreme. You don't have to practice 200 times to create a winning a presentation. But you'll have to practice more than you think. Here are five steps to rehearse effectively. 

1. Start with presentation notes.

In PowerPoint, you can write notes at the bottom of each slide. Start writing notes for each slide in full sentences. Read the transcript out loud as you review each slide. Next, cut down the full sentences into bullet points and rehearse out loud again--relying on notes even less. Eventually, cut the notes down to just a few words that will prompt you to deliver the entire concept. The less you rely on notes for your final presentation, the more eye contact you'll make and the stronger your connection will be.

2. Practice under 'mild stress.'

Psychologists who work with athletes have found that mirror real-world conditions as much as possible during practice sessions brings out the best performance when the pressure is on. The famous entrepreneur and author, Tim Ferriss, applied this concept to his TED talk. "Mimic game-day conditions as much as possible," he said after his presentation. Ferriss gave the presentation in front of friends and strangers at various startups to groups of about 20 people. "I don't want my first rehearsal in front of a large group of strangers to be when I stand up in front of 3,000 people," he said.  

3. Ask for specific feedback.

Once you've practiced your presentation in front of a small audience, most people will say "good job." They don't want to hurt your feelings and they'll have limited feedback. While "good job" might help you feel good, it won't help you get better. Ask them to be specific: Is there something you didn't understand? Do I use jargon that you're not familiar with? Did I make strong eye contact? What did you like--or not like--about my delivery? What can I do to make it stronger? 

The musician, Amanda Palmer, invited more than two-dozen people to a watch her practice over a potluck-style dinner. She delivered the talk to students, she gave the presentation to friends over Skype, and did two or three rehearsals in front of TED organizers. She spent countless hours to get it right over a period of four months. Each time, she received feedback and tweaked the presentation--re-writing parts of the script--to condense it into 12 short, powerful minutes. 

Ask friends and colleagues for open, honest, and specific feedback

4. Record it.

Set up a smartphone or a video camera on a tripod and record your presentation. You'll be surprised at what you see. You'll catch vocal fillers such as 'ums' and 'ahs.' You'll find yourself using distracting hand motions like brushing your hair back or jiggling coins in your pocket. You might catch yourself avoiding eye contact or looking at the slides more than you're looking at the audience. It's not always comfortable watching yourself on camera, but it's a critical tool for successful presentations.

5. Practice until it's effortless.

The hardest question to answer is: How many times should I practice my presentation? Dr. Jill practiced 200 times. Author and scientist Mary Roach practiced 25 times for her TED presentation. I recommend rehearsing the entire presentation until you can deliver it effortlessly, without thinking about the first words you're going to say about each slide. In my experience as a professional communication advisor, I put the number of rehearsals at 10. Some people might need more; others need a little less. But if you practice your presentation from start to finish at least ten times, you'll have more confidence than ever. 

You might not be giving a TED talk, but a high-stakes presentation in any format requires an extra level of preparation and rehearsal.