And yes, it is true, there are definitely some costumes out there which do not piss me off.
I was thinking about two particular costumes while considering what my own lines are (but if you want a nice comprehensive list on whether or not you should do this outfit you really want to do, Thursday of the Sadness of Pencils has a pretty good list). I've mentioned them before, too: during Nova Albion, I saw a terrible outfit which appeared to consist of disparate Random Asian Things pulled together into some semblance of a peacock-themed outfit. The other is a traveler's outfit at GearCon.
What's the main difference?
The first outfit, though it looks like a lot of love has gone into it, doesn't make sense. In no historical period would anybody be wearing a giant fan at their backside to approximate a peacock that I can think of. Staring at it, I couldn't place what or where this person is supposed to be, except at some a-historical space where one can apparently pull random shit together.
Outfits, to me, generally ought to have some sort of sense, even if it's a bit of a stretch. Even if it means really stretching. This Cthulhu bustle, for example, is a bit of a stretch. But you can tell where it comes from: Lovecraftian lore, combined with a Victoriana-inspired outfit.
The fact that outfits really should have sense is even more imperative when you're not using an outfit from your culture. And I really wish people had more of an explanation for why they're doing it besides "I love this [usually non-white] culture." I get it if you're not white and you're wearing white fashions, because assimilation and the imposition of white culture has been pretty widespread. That's what colonialism is all about. But the only reason I can ever think of, for white people using non-white cultures, is this sense of entitlement that's so often on display: "I SHOULD be able to!" Cue racist bullshit about post-racism, culture-belonging-to-anybody, you're-racist-for-noticing-racism-and-harshing-our-squee.
There are totally outfits that make sense, even when non-white on white bodies.
Dude I met at GearCon, for example? His was a traveler's outfit. It was a plain white shirt, and a shawl, and loose trousers, and a pointy straw hat. I really liked it. Why? Because it made sense. It is entirely possible that a white dude would be traveling in Asia, and he'd adapt these random things, which have some goddamn function, by the way, not like a bustle in the shape of a giant fan, into a workable outfit for traveling. It's comfortable, looks sturdy to protect against the elements, and even though I can't exactly place the outfit historically, it looks like something that belongs on the Silk Road. It looks like something an actual traveler would wear.
I've only been able to articulate this because other people have already done it, of course. Monique Poirier recently took an attempted NDN steampunk cosplay to task for its appropriation:
If you want to dress as a character who wears NDN attire, be prepared to have a backstory that explains why you, a white person, are wearing it (please not ‘My character was adopted into X tribe!’ either as a child or later in life or through marriage when they fell in love with a Badass Native/Chief’s Beautiful Daughter - that is the most overplayed Mighty Whitey bullshit fantasy ever and for fuck’s sakewhen, when, WHEN will white people get tired of it? I cannot tell you how many white people I have heard expound unto me thier Dances With Wolves or Little Big Man or Every Third Romance Novel With NDNs In It backstory. Shit gets old, and you do not have enough we-sha-sha.). Do some historical study on what characters might be likely to do this (fur trappers and prospectors come immediately to mind). Know that some things are never, ever ok to wear (war paint, feathered headdresses, ESPECIALLY war bonnets, specific religious symbols, etc.) and that evern of you think you’ve done all your homeworks, NDN people might still be pissed at you and that they are right to be so. If you’re not willing to do this, to take these extra steps, then just don’t do it.
Stop and think about why you even want to.
Note the bit about fur trappers and prospectors. Those were real people, who interacted a lot with NDNs and therefore, it makes sense that they would be wearing some NDN attire as a result. When people bleat about "cultural exchange", I doubt they're actually thinking about situations like this; too often, I get a sense of "cultural exchange" being "I SHOULD be able to!"
The first outfit, because it makes no historical sense, nor even functional sense, ends up being a caricature of Asian Things, drawing on everything that looks Possibly Asian to create an image that Looks Asian, but doesn't actually say anything besides the fact that this person that the wherewithal to buy Asian-Looking-Things. And you know what? White people pulling random Asian-looking shit together is part of white privilege. It reminds me that a white person can do this and they can take it off later and not suffer for it; that it's only a costume, and thus meaningless when taken apart.
I don't even trust that GearCon dude did homework or has a profound sense of respect for Asian cultures. I can't read that from his outfit. What I can read is that it's historically-logical that a white person in Asia would be wearing such an outfit, and that signifies a story. And fine, white Orientalists traveling the depths of Asia, that's not a new story either. But it's a story that potentially engages with Asia and Asians, as a fellow human being, not as a consumer.
And that makes a real difference in how I'm going to feel about an outfit.