If you wonder why so few women are running Fortune 500 companies, it’s because they lack “executive presence.” That’s not our opinion, but the results of a revealing study that’s summarized in a special @WORK supplement in Marie Claire magazine.

Looking and Acting the Part

In the view of Sylvia Ann Hewlett, founder of Center for Talent Innovation (CTI) the think tank that conducted the study, these are the traits that will make you a contender for the top spot:

• How you look
• How you speak
• How you behave

“Nailing these three things makes you a contender,” she says. They are essential to what she called the “Big Picture,” or the traits that are the most important aspect of executive presence: gravitas, communication and appearance.

Surprising to us, both women and men in the sample of 4,000 white-collar professionals ranked the relative importance of these traits almost exactly the same.

Gravitas — which among other things includes being, decisive, authentic and inspirational — is considered the most important quality, by far, that you need to get ahead, with more than 60 percent of both sexes ranking that first.

Appearance Counts

Fewer than 10 percent of both women and men considered appearance important. Yet Ms. Hewlett considers wardrobe a crucial factor in executive presence, “It doesn’t seem that important, but it’s a critical piece of the puzzle because it’s the first filter.

“If you show up looking sloppy and as if you don’t care how you look, no matter how impressive your ideas are, no one is going to pay attention to you. People take you more seriously if you look polished,” she added.

These guidelines apply to both women and men. Recently, we coached a top executive who was giving a presentation to 500 of his client’s most important customers. Tony is good looking, polished and well prepared. He looked great in his well-tailored suit –until he walked from one side of the stage to the other.

That’s when his wing-tipped shoes were literally front and center. He had substituted orange shoelaces for the black laces that came with the shoes because he had read a Wall Street Journal article that said men could have some fun and express their personality by wearing colored shoelaces.

Sure, that’s great on a weekend, or on your running shoes, but not in front of a conservative audience that you want to persuade to your point of view. While he did a great job on his remarks, the orange shoelaces were a distraction and took away from his gravitas.

The seemingly little things are the ones that count!

When working with a group of doctors from the Netherlands, a Key Opinion Leader was invited to speak to the Dutch physicians. Those of us who knew the speaker were used to her “look” and were not surprised by her usual baggy black clothes, the clogs on her feet or her mane of long, disheveled hair

During the break, the Dutch doctors pulled me aside to tell me how insulted they were over the way this specialist presented herself. Her dismal appearance made them feel they weren’t important enough for her to make an effort to dress appropriately.

Even Mark Zuckerberg, the vaunted founder of Facebook, irritated the investment community when he showed up at the New York Stock Exchange in his celebrated hoodie instead of the Wall Street uniform of business suit, shirt and tie.

Again, appearance matters!

Mistakes to Avoid

Women in the study were their own harshest critics. These are their biggest no-no’s when it comes to at-work appearance:

• No bra – 74%
• Too-tight clothing – 68%
• Unkempt hair – 67%
• Visible lingerie/panty line – 50%

We’re not surprised at these findings because during the course of our training sessions, we often see women making these same mistakes.

It’s critical for women — and men — to create a professional image.

We tell our clients that what you say is important, but a first impression is formed by your appearance before you even begin to speak.

Your personal style, or image, is a silent introduction of yourself to others. Whenever you walk into a room, your clothing, personal grooming and body language are on immediate display.

Women don’t project gravitas when they enter a meeting with messy hair or wear inappropriate attire such as a dress that is too short or too low cut.

For a man, wearing an earring, no matter how small, doesn’t project a corporate image. A wrinkled shirt or suit is another common mistake. We’ve told male clients that they resembled an unmade bed and that a wardrobe upgrade was necessary. And, yes, these same executives still work with us.

How You Speak and Behave

As Ms. Hewlett points out, it’s important to know the simple rules of engagement. Speak up and use power words such as “I’m confident” rather than “I think”.

Be aware of your body language because that will speak louder than any words you use. Continue to maintain eye contact and be attentive to the person you’re talking to. Glancing at your smart phone for the latest email is rude and disrespectful.

It’s essential to become more assertive to persuade people to accept your ideas without appearing “pushy,” a pejorative that’s unfortunately applied to women more than men.

How you look, how you speak and how you behave are all part of your overall image. During NYC’s Fashion Week, Michael Kors was asked what advice he had for people before they hit the stores. Kors’ reply was priceless. He said, “get a three-way mirror.” That’s great advice for everyone!