They say "clothes make the man", and if that rule of thumb ever did apply it would be in professional wrestling. However, in the past few years many of the wrestlers have been spending less on their ring gimmicks, resorting instead to street clothes, something that robs them of tremendous pieces of character. Many seem more interested in peddling their tee shirts than creating a presence. When people say that wrestling has changed in recent times, this has a lot to do with it..
Much of the industry is rooted in broad theatrics, like that of a stage play or musical. The idea is to get your message across to ever single member of the audience, even up in the nosebleed section. When you step out into the arena, your look should immediately say something about your character. Few will ever get the chance to have big screen monitors focusing on them, so working broad is the natural way to attract attention.
When you ignore dressing for your part, you are killing off one of your best devices for getting over with an audience. In some instances, a flashy costume has helped define identity. Tee shirts and jeans just don't have the same impact. It would be like "Nature Boy" Ric Flair wearing Levis and pennyloafers -- he would not be Ric Flair. Imagine Jerry "The King" Lawler without his cape and crown, or the Honky Tonk Man without his Elvis suits. Their costumes make them seem larger than life, and when you break it down, wrestlers are basically paid to be superheroes.
It all goes back around 50 years ago, to Gorgeous George, who was the highest-paid and most iconic star of his era. He knew that wrestling was a visual medium. The wrestling was always important, but the gimmick was the ultimate form of advertising. His approach helped to re-define the business.
A proper outfit is a tool that can and should be used to further your character. It is a device that adds interest, as well as drama. Rick Rude used his robes during his striptease act to enrage the fans. The arrogance of "Gentleman" Ken Timbs was enhanced greatly by his large and flamboyant wardrobe. The Valiant Brothers always played their city slicker role to the hilt, dressed to the nines. Greg "The Hammer" Valentine, one of the most callous and brutal men in the industry, was given an air of class and distinction by wearing his magnificent robes -- an element that helped bring his character to another level.
Your wardrobe should be seen as a prop, and you should view yourself as a performer. An actor won't go on stage or in front of the camera without wearing make up or putting on his costume, and you should not be without your tools of the trade. People expect you to look different -- it is part of the business, just as much as the wrestling, itself.