Tailoring of the jacket on slim men is the first mistake that comes to mind. Many men like to buy off the rack suits, (which is fine with proper tailoring). However, a thin man will almost always have to get the waist taken in to make the suit sit appropriately on them.

The buttons on a suit jacket should never all be used. Bottom buttons are never to be buttoned and top buttons on a three button suit do not need to be buttoned.

The sleeves on a jacket should be short enough that a quarter of an inch of the dress shirt is showing but not more. Many people buy suit jackets that fit perfectly except for this area, don't be one of them.

Pants with a flat front should never have cuffs. Save the cuffs for your pleated and double pleated pants.

Pants should come to an end with a slight break at the bottom. Many men buy pants that are too long for them. This can only lead to a pair of suit pants with a ragged looking bottom.

The color of the belt should always match the color of the shoes.

Shoes that need to be polished should always be polished. There really is no excuse for having grossly unshined shoes.

Wear socks that are a shade lighter than the suit pants. This rule applies to everything but a white suit. Never wear white socks.

Read and study this article the next time you decide to put on a suit. Take notice of your mistakes and correct them. The time it takes to look good is is a worth investment.