Being a way of life which gives guidelines to all aspects of lifestyle, Islam also provides for codes of public decency. While there is no hard and fast rule to Islamic clothing, there are particular types of clothing that Muslims have to wear as a minimum standard that they have to comply with.
These rules originate from two main sources, namely: (1) the Qur'an, known to be the word of Allah, and (2) the traditions of the Prophet Muhammad (known as the human role model), called the Hadith.
The first set of requirements in Islamic clothing deals with the particular body parts that should be covered. Generally, women are called to cover her body, especially the chest. As for the Prophet Muhammad, he says that women should cover their bodies, save the hands and the face, which implies that head coverings are required as well.
The extent of the body parts required to be covered by men is not as vast, since they're only required to cover the parts from the knee up to the navel as a minimum.
The second requirement on Islamic clothing pertains to looseness. The rule is that the clothes must be loose enough so that the outfit doesn't reveal the outline of the body. This means that it's a no-no for men or women to wear anything skin tight or otherwise tight fitting. Women are even required to cover their "curves" by putting cloaks to conceal their personal clothing.
The same rule of looseness applies to men, their traditional dress consisting of robes that flow from the neck down to the ankles.
Apart from being loose, the clothes, as stated in the third rule, should be thick enough. That is, the clothes must not be made of fabric so thin that people can see through it, simple because it's not modest. Neither the color of the skin nor the shape of the body must be seen through the clothes.
As a fourth rule, both men and women have to appear modest and dignified. Too much flashy and shiny clothing are inconsistent with the whole idea of modesty, so they're highly discouraged, although not necessarily prohibited.
The rest of the rules on Islamic clothing extend beyond the specifications on the clothes itself. Beyond clothing, a particular conduct and mindset must also be observed with respect to these clothes.
Men and women Muslims must never try to imitate the clothes of other people of other religions. This means that they have to be proud of what they're wearing and who they are in general. Women are expected to take pride in their femininity and not wear the clothes of men. Conversely, men are expected to not wear accessories and clothes that are considered for women.
But at the same time, the pride in one's clothing should go to the extent that it foregoes the values of humility. Islamic clothing must not be too flashy or extravagant looking. Muslims must dress modestly, and not simply to impress others or get their sympathy.