Mistake #15: If you are not good at something, don't do that something in front of the camera.
Over the years, Walters has done a lot more than just ask the questions in her interviews. She's tried her hand at some of her guests' favorite activities, from shooting hoops with Shaq to lifting weights with Arnold Schwarzenegger.
#14: Dancing is fine; stripping is out of the question.
Walters has taken a turn on the dance floor with stars like Al Pacino and Patrick Swayze, but Demi Moore went one step further. She had a new movie called "Striptease" out in 1996, and offered to teach Walters how to dance like a stripper. The lesson? It was not a good idea to teach Walters how to dance like a stripper.
#13: Never ask me to sing, because I will.
Many of Walters' guests have broken into song for the cameras, but a few, like Billy Crystal and Dolly Parton, have made the mistake of asking her to sing along.
#12: Never compete with a cartoon character.
What's even trickier than interviewing a big star? Interviewing a big star who isn't real. Walters has taken on the Teenage Mutant Ninja Turtles and Shrek, only to discover that some things are better left for Saturday morning cartoons.
#11: Don't pretend to be hot when you're not. When talking to hot, young stars like Paris Hilton, Will Smith, Beyonce and Kanye West, Walters tries to show that she, too, is hot, jiggy with it, and all-around bootylicious.
#10: If I say you're fascinating, please don't deny it.
Every year Walters interviews the "10 Most Fascinating People of the Year" for her special. But some guests, like Oprah Winfrey and David Letterman, challenge their nomination to the list.
#9: Never grant me an interview unless you are prepared to deal with all the emotional issues in your life.
Some stars forget to bring the Kleenex to their interviews, even though Walters is known for making everyone from Courtney Love to Patrick Swayze cry.
#8: The entire Warren Beatty interview.
He's wonderful and a talented actor, but Walters learned that Warren Beatty didn't always make for a great interview. The questions got longer, and the answers got shorter.
#7: Call Teri Hatcher every month, just in case.
Teri Hatcher asked that a poignant portion of her interview with Walters not be run. A month later, Vanity Fair magazine shared the story of how Hatcher was molested by her uncle as a child.
#6: Predicting the future can be dicey.
Walters commonly asks celebrities where they think they will be in 10 years, and she's gotten some truly outlandish predictions.
#5: Unless someone is openly gay, it's nobody's business — including mine.
Walters openly discusses sexual orientation with Boy George, Drew Barrymore, Ellen DeGeneres, and the Fab Five from "Queer Eye," but she regrets asking Ricky Martin to address the rumors about his sexuality.
#4: Drugs are bad.
Through the years, Walters has talked with stars like Ozzy Osbourne, Kirstie Alley and Johnny Cash about drugs.
#3: Don't call one famous celebrity by the name of another famous celebrity. In one of her most embarrassing moments, Walters accidentally calls Arnold Schwarzenegger by the name of another famous celebrity.
#2: The mistakes that escaped.
Walters wants her celebrity guests to know that if she interviewed them and it didn't end up in the special, it's her mistake.
And the #1 mistake? The biggest mistake of all would be giving it away. Tune into "The Barbara Walters Special: 30 Mistakes in 30 Years" to find out what tops the list.