In the Holy Temple, the clothes worn by the kohanim (priests) were a simple affair - robe, pants, hat and belt. All of them completely white. That was it. Enough to do the job of clothes - cover the nakedness - but no more. Apparently, clothes maketh not the man - especially when in service of God.
The first time we encounter clothes in the Torah is at the time of their invention. In the Garden of Eden, Adam and Eve are naked. But once they eat from the Tree of Knowledge, they cover themselves. In their pure and naive state, they were able to relate to each other on a purely spiritual level. They were not distracted by the desires of the physical body. So they did not need clothes.
However, once they transgressed and their desires became more prominent, they became attracted by the physical body and needed to cover it, if they were not to become distracted. The purpose of clothes was to enable human beings to relate to each other as just that - human beings, and not animals. By covering the physical, the spiritual is emphasized.
It's funny how the world has changed.
Clothes nowadays have actually become an expression of the physical. They emphasize form and shape. They attract with color and design. They create status - albeit a false one. Instead of focusing us on the Godly soul in those around us, they do the precise opposite. They distract us from who a person really is, by creating a superficial impression.
The clothes of the kohanim were simple, because their actions did the talking, not their clothes. Looking good can be a cheap substitute, a counterfeit pleasure that gives a brief illusion of the sense of perfection and beauty that we all strive for.
Yes, it's important to look neat and presentable. But in Judaism, more important than "looking good" is to "be good." Don't be content with making an impression by how you dress; rather become a person whose actions truly count.