A manufacturer's representative I know recently took a group of contractors on a plant tour. Nearly all of the builders wore jeans. "Marty," the factory rep, was dressed in shorts, sandals and a bold tropical shirt. He hardly projected the image of a business leader.

Meanwhile, Marty's direct client–the middleman between the manufacturer and the contractors–was dressed smartly in gabardine slacks, a freshly pressed dress shirt, and polished black shoes. Marty may have matched the style of the contractors, but he wasn't up to par with the person who mattered most to him: his direct client.

Marty made the same mistake committed by many LBM salespeople: They dress seeking to fit in with the clothing style of their clients. The problem with this notion is that today's business climate takes you from the jobsite to the board room in minutes. One client might be clad in jeans while the next might be wearing a coat and tie. How can a salesperson look like all of them?

I say: Don't try. Rather than striving to blend in, project a level of authority on which people can rely.

Robert Cialdini, a Stanford psychologist, conducted a study in which he concluded that authority was one of the six most critical factors in creating influence. Appearance is a critical factor in creating that sense of authority, and the clothing you wear speaks volumes about your professional status. Lawyers wear suits. Doctors wear white jackets. Successful business leaders wear business casual dress clothing. It's that simple.

Clothing is a uniform that should reflect your professional position, not your choice of personal style or what your customers are wearing. Shorts and dirty blue jeans are for amateurs. An LBM salesman can always count on the credibility of a pair of khaki slacks and a simple button-down collar oxford cloth shirt. To ensure the look of professionalism, get your slacks and shirt professionally pressed at a local dry cleaner. If you are more comfortable in a polo shirt, that works so long as the shirt looks fresh and clean. A solid pair of hard-soled shoes, even work boots, makes the statement that you're ready to work, while the slacks and shirt speak to your professional credibility.

Gym shoes are always a mistake.

But I hear you say: "Last month, you told me that Jackie Allmond is the best outside sales rep in America (see "Top Gun," October issue), and he wore jeans." But Jackie is different; with his sales record he's earned the right to be eccentric. I'm reminded of the minor-league rookie pitcher in Bull Durham, Nuke LaLoosh, who had fungus on his shower sandals. As Nuke's mentor Crash Davis tells him: "You'll never make it to the bigs with fungus on your shower shoes. Think classy, you'll be classy. If you win 20 in the show, you can let the fungus grow back and the press'll think you're colorful. Until you win 20 in the show, however, it means you are a slob." Good advice. You might be able to get away with dressing down, but why risk it?

There's an old story about an archetypal Harley-Davidson rider who walked into a bank with $25,000 to open a new account. The surprised, clean-cut banker in a dress suit asked the burly, leather-clad biker with a four-day beard: "What made you trust a man like me, someone who hardly fits in with you?" The Harley rider replied: "Would you give your life savings to a guy that looks like me?"

Dress in a way that creates authority and you'll achieve better results in the long run.

Rick Davis is president of Building Leaders Inc., a Chicago-based sales training organization.
E-mail: rickdavis@buildingleaders.com