So, the purpose of fashion should be limited to beautification. It should not enter weirdness or nudity. Many a fashion trends of today's age do not comply with the actually meaning of fashion. Such fashions have no place in islam. But other than this, islam is a religion where beautification and looking good is encouraged. Allah swt say in Quran;
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)This verse shows that clothing is not only to cover up but it is also for beautification. This verse rejects the views of narrow minded people who think that good muslim is the muslim who would be simplest. Of course, simplicity is the best, but it should not restrict one from looking good and decent. Unlike the most modern day stupid and weird designs and clothings that are far from decency, islam likes decency and elegance. So dress up and appear as decent and as elegant as you can. In another verse, Allah swt say;
O children of Adam! Wear your beautiful apparel at every place of worship, and eat and drink, but do not be wasteful.... (7:31)This verse tell us that our worship requires us to wear our beautiful and best clothes. Therefore, the second thing about looking good and clean is that without it, our worship may not be accepted. We all like to look good when we go out and meet family and friends. We all do that because we all want to leave a good impression on others. In the same way, Allah swt require us to look good and clean when we appear before Him. Surely, Allah swt has the most right on us than any other being.
As said earlier, islam is all about looking decent and elegant. But satan likes it the other way. He likes human beings to look the way they would displease Allah swt. Why so? Only because he is our enemy. He thinks that it is because of us that he was torn from his status. So he sworn to take his vengeance on us. This is why he leads us to do all that would displease Allah. In the same way is the matter of clothing... or put the modern way, fashion. There is a verse in Quran which describes the real mentality of satan;
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)When Allah swt created Adam and Eve, He (swt) put in them haya and elegance. Allah swt gave them cloths to wear so that their sense of shame and haya could be at peace. When satan seduced them to disobey Allah swt, they were expelled, they were stripped off from their clothes. They both started to cover themselves up with the leaves. This was the poisonous way of Satan. From the very start of the human race, satan has been trying to stirp the humanity off of its shame. In every age, he has succeeded to some extent in this. So all the new fashions that include showing off of body whether with tight clothes of without cloths is all but satan's plan. Once the haya is gone, the iman is gone. This is why haya is called of of the branches of iman.
Fashion is not the name of showing of body, instead fashion should be enhancing the already beautiful self. Allah swt says in Quran that He has fashioned us is beautiful way, when He has made us beautiful, we should thank Him by looking the way He wants us to look. Doing fashion is not sin, but adopting satanic ways surely is.