When I think of Garak, the tailor, and I see the costume design in DS9, what comes to my mind is that fast-fashion is dead.
There are some Bajoran clothes' shops in DS9 but there is also a tailor. What we see of Cardassians is that they care about their tailored clothes, so of course there was a tailor in a Cardassian station, but there is still one now that the Cardassians are gone (and he is Cardassian).
On the one hand, this speaks of Cardassian culture and maybe a Cardassian stereotype regarding clothes. But also, in a broader approach, of how clothing works in this world.
Ferengi also care a lot about their clothing choices, they have layer on layer, it shows how much money and profit they have. It is also tailored. Bajorans and Humans seem to be more careless about the fashion choices and while things are their size, the emphasis is not necessarily on "tailored". Generally speaking, comfort is the main trend (except for Lwaxana).
Generally speaking, most clothes are more or less tailored, but it is interesting that there is an official tailor, not a seamstress, not a dressmaker, although I guess those exist too (especially in societies where money exists as they tend to be cheaper). He speaks of creating new patterns that he takes to the replicator. He also speaks of modifying clothes (that are either bought in shops or replicated, I guess), probably because the replicator works with standards.
But even a replicator is no necessarily instant. It may be for food or drinks, but is it also the case for a dress? For a coat?
We see that they repeat the same clothes often. The first seasons, Jake has a couple of onesies he wears a lot, until he outgrows them. O'Brien has a blue shirt that he wears often. Kira has a red originally knitted cardigan and mustard pants.
This means that clothes are long-lasting, that fashion as a trend is not as important as in other moments in history. Clothes are made to be comfortable and to last, and people who know how to make and mend clothes are valued and necessary. And some things, a replicator could never do anyways.
There are also probably new types of natural fibers discovered in certain planets. I haven't seen Ferenginar yet but I know it rains a lot, so they probably have good waterproof materials (as in treatment of fibers) or even waterproof fibers. I bet this whole look Quark has is waterproof but breathable.
Ferengi women are very likely responsible for making the clothes for their men, they are skillful spinsters, dyers and knitters. The poorest of the Ferengi, those who are unable to make profit, are also probably the ones working in the fields to grow the fibers needed. Sure, many of these tasks could be replicated but why bother when you can use them to show who is in charge?
Bajor must have good breathing fibers similar to cotton or linen (more like linen than cotton as it doesn't seem too stretch generally). And they are particularly skilled at dying lasting colors. They are also creative knitters. Bajoran uniform includes a knitted pattern in their t-shirt.
Cardassians know how to work the fiber to make them stretch or they probably have fibers that naturally stretch like wool (many of their clothes seem to be made of wool-like fabrics). What animals does Cardassia have and how is their stockbreeding?
Klingons, on the other hand, probably prioritise leather-like clothes. So similar question arise: how is their stockbreeding? I gather is a honorable task highly rewarded, as it must be all the leather industry too, especially if it is uniforms for battle. They may also have silk-like fibers, as good silk is difficult to puncture for civilian clothes, along with other animal originated fabrics.
The only thing I have to add here is that Kira's red cardigan is crocheted, not knitted, which is really interesting in and of itself, because crochet must be handmade, where knitting can be done by machine. Theoretically a replicator could do both but I don't think it matters. The episodes that she wears it in are usually resistance-oriented, and I wonder if it was handmade in the resistance. They wouldn't have had access to replicators, so clothing would need to be handmade. Here also, the stitch that's used to make the cardigan is something that could be made incredibly fast. With chunky yarn and a big gauzy stitch, a skilled crocheter could make that in an hour or less. We can see how this, compared to the green, is born out of need and utilitarianism, because of its quick design and handmade appearance.
This is in stark contrast to the knitted green dress-cardigan, which is made from a much more delicate fiber, and is clearly not made for the rugged environment of the resistance. It's knitted lace, probably of a sport-weight yarn. This is not going to hold up if it gets caught on something, unlike the red cardigan, and unless it was machine knitted, it would take skilled knitters weeks to make by hand. We only see this in Bareil's temple, once the resistance is over, and it shows Bajor's healing, even through its clothing. It's truly brilliant on the customer's part, because we can tangibly see the resurgence of Bajoran artisans. They're no longer held back by necessity.
