The question of how Attire words come into being is very nearly as varied as the language itself. When we scroll all the way back to our proto-human selves, the wearing of an animal skin could have gained different meanings, depending on how it was worn. Certainly in terms of modern psychology, to wear that skin over the head would imply the control of the spirit of the animal, over the loins it means something entirely different, more along the lines of subjugation through physical power. So even in the dim past, the words we had became more diverse, every time a new method of dealing with it came by us.
This continued to be dominantly the case for quite a long time through human history. Sure the upper classes had their fashions and trends and novelties, but they did not impact the common run of people in the way that they can now.
It wasn't really till the late Renaissance that the apparel of the upper classes began to affect the other classes, and vice versa. By the middle of the 1500s, the common run of folk were wearing clothes that were radically simplified versions of the togs of the elite. This continued, and frankly, still does. The Humanist movement helped this process along, by endowing the common people with a dignity they had been denied, previously.
What changed next was that the attire of the masses began to affect the upper class. During the late 18th century, with the rise of influence of writers like Voltaire and Rousseau, there was a concomitant rise in interest in the life, pursuits and manner of the majority of the populace by the ruling classes. Sure, their clothes that aped the dress of the multitude were of the finest fabrics, and decorated in ways that the poorer folk could never dream of, but, nonetheless the Attire words they were using had been created, first by the commonality of the populace, then re-defined by modistes and milliners and tailors.
This quantum leap of new words has continued, unabated, through to today. Now, every single day, hundreds, possibly thousands of new words are added to the Language of Attire.
But, something has happened that makes it much, much different than before. Now, instead of the majority of the new words coming from the average person, they come from people who are paid to do exactly that, come up with new words for us to wear. One of the fundamental roles of a designer of clothes and accessories is to add to the dictionary of words we can use. And yes, it is true that many designers draw their inspirations from the streets, but it does not invalidate the fact that they create new words in the process, just as their 18th century predecessors did.
It remains to be seen whether or not this is ultimately a good thing.