The word or phrase you should pick will depend on the context that you want to use it in.
If you want it to mean exactly what your question states (self-created) and are using it as a single-sentence explanation somewhere, there isn't a single, concise word that I know of that will do this. You will have to pick a phrase that (I think) will sound clunkier, and the best phrases use the auxiliary verb do, not be (is), which ruins the symmetry between your two sentences.
If you are intending to use it as a piece of poetic language to more stylistically get your point across, e.g. as a slogan, or as part of a longer essay where the sentiment is explained more fully, then you can use language that doesn't mean exactly what you want say, but carries something of the correct connotation.
If the former is the case then you could use the phrase "just appear" (or "just appear out of thin air", or "just appear out of nothing"). The use of "just" gives emphasis to the effort required.
Fashion doesn't just appear. It's made.
If the latter is the case, and especially if you think your audience has a significant Christian makeup, then you could use the word begotten. Begotten essentially means "fathered", so carries the same sort of meaning as "born", but one of the most famous uses of the word is in the Nicene Creed (which many Christians will know) in the line "begotten not made". Saying the opposite of this famous quote would give it some poetic style. That said, the word is "church language" and quite old-fashioned, so it could sound odd to some people.
Fashion isn't begotten. It's made.