1. The Lawful and Unlawful
In regards to Clothing and Adornment

2. Islam permits, and in fact requires, that the Muslim be careful about his appearance, dress decently, maintain his dignity, and enjoy what Allah has created for the purpose of clothing and adornment.
From the Islamic point of view, clothing has two purposes: to cover the body and to beautify the appearance.
Allah counts His bestowal of clothing and adornment upon human beings as one of His favors to mankind:
“O children of Adam! Verily, We have bestowed upon you clothing to cover your shame as well as to be an adornment to you.... “ (7:26)
Whoever neglects either of these two aspects, covering or adornment, has deviated from the way of Islam toward the path of Satan.

3. Accordingly, Allah warns people concerning both nakedness and neglect of good appearance because they are traps of shaytan:
“O children of Adam! Do not let Satan seduce in the same manner as he expelled your parents (Adam and Eve) from the Garden, stripping them of their raiment in order to expose their shame.... “ (7:27)
“O children of Adam! Wear your beautiful apparel at every place of worship, and eat and drink, but do not be wasteful.... “ (7:31)
Islam has made it obligatory on Muslims to cover their private parts, which everyone naturally feels a sense of shame at exposing in order that they may be distinguished from the naked animals; in fact, it instructs them to avoid uncovering these parts of their bodies even when they are alone so that they may attain perfection in morals and religion.

4. We have the following authentic hadith to prove the above wherein a man came to the Prophet and asked:
'O Messenger of Allah! What should we conceal and what can we show of our private parts?' He replied, 'Let no one see them except your wife or your bondwoman.'
I then asked, 'What if some people live together (e.g., during travel, or camping)?' He replied, 'If you can manage it, try not to let anyone see them '
I then said, 'And what if no one is present (meaning if one is alone)?' He said, 'Allah is most deserving of your modesty.'
(Reported by Ahmad, Abu Daoud, al- Tirmidhi, and Ibn Majah.)

5. Before directing its attention to the questions of adornment and good appearance, Islam addressed itself in considerable depth to the question of cleanliness, for cleanliness is the essence of good appearance and the beauty of every adornment.
The Prophet said: "Cleanse yourself, for Islam is cleanliness." ( Ibn Hayyan.)
"Cleanliness invites toward faith, and faith leads its possessor to the Garden.
(Tabarani.)
The Prophet placed a great emphasis on keeping the body, clothing, houses, and streets clean, and he laid special stress on cleaning the teeth, hands, and hair. This emphasis on cleanliness is not to be wondered at in a religion which makes cleanliness the key to its principle form of worship, salat, for the Muslim's salat is not acceptable unless his body, clothing, and the place where he performs his salat are all clean.
In addition to this requirement' there are the obligatory types of cleansing, either of the entire body in the form of ghusl (total washing), or of those parts of the body which are exposed to dirt, in the form of wudu (ablution for salat).

6. Once a man approached the Prophet with his hair and beard disheveled
The Prophet made some gestures as if asking the man to comb his hair. He did so, and when he returned the Prophet said to him,
"Is not this better than that one should come with disheveled hair, looking like a devil?" (Muwatta.)
On another occasion the Prophet saw a man with unkept hair and remarked, "Does he have nothing with which to comb his hair?" ( Abu Daoud.)
Upon seeing another man with dirty clothes he remarked, "Cannot he find anything with which to wash his clothes?" ( Abu Daoud.)

7. More hadiths illustrating the importance of good appearance and not walking around lookin shabby tacky and cheap:
A man came to the Prophet wearing cheap-looking garments. "Do you have property?" the Prophet asked him. "Yes," the man replied. "What kind of property?" asked the Prophet. "Allah has given me all kinds of wealth," he said. The Prophet then said to him, "Since Allah has given you wealth, let Him see the effects of His favor and bounty upon you.'' ( al-Nisai.)
Also the Prophet insisted that people come to general gatherings, such as the Friday and the 'Eid prayers, nicely dressed and well-groomed. He said,
“If you can afford it, it is befitting that you wear garments other than your working clothes to Friday prayer.”
(Abu Daoud.)

8. So thus we see the importance of maintaining a good and clean appearance as Muslims
Doing so brings one closer to Allah and makes the person who who is living the sunnah or example of our Prophet.
It must be noted that these standards apply to men and women for Allah does not discriminate.