writing about hanfu: a guide
so! you have learned what "hanfu" is! congrats!
now i have to tell you, very politely, to forget the word "hanfu".
in most xianxia or historical chinese settings, where characters are assumed to be speaking in chinese, &/or have never been outside of china? all "fu" (clothing) is "hanfu" by default.
because most chinese people (mainland AND diasporic!) are han chinese and han chinese have been the ruling majority for pretty much all of china's history.
(primary exceptions are the mongolian-lead yuan dynasty & the manchu-lead ming dynasty but, in chinese fiction, it is always non-han chinese garments that are specified as such)
with this history in mind, it is almost always anachronistic to specify to chinese characters that something is chinese: the term "hanfu" was only invented when western dress became the assumed default!
so, when incorporating traditional chinese fashions in your english language work?
use descriptors such as "wide-" or "long-sleeved" when meaning these kinds of top garments
"frog-buttoned" or "wide-collared" when referencing manchu shirt styles (such as the modern qipao/cheongsam)
"trousers" is valid (if you're worried about being misunderstood, you can specify that they're "silk" or "wide-legged")
"robe" or "dress" for a single layer of full body hanfu; "robes" for multiple layers.
underwear is anachronistic pretty much everywhere, historically: historical dress uses an "inner layer" or "inner robe" for hygienic purposes. "shift" works too but is more associated with medieval european dress.
if looking up the history of sanitary napkins or loincloths feels daunting, you could sidestep the issue entirely with "undergarments".
"boots" or "slippers" for shoes (but you can also just say "shoes")
no one is wearing heels unless they're from a video game
"stockings" for socks
fabrics can be safely assumed to be "silk" (rich elite/inner layers of the middle-class); "cotton" or "linen" (commoners/inner layers/when exercising). you can also just say "cloth" or "fabric".
(other fabrics did exist historically, wool & hemp for example, but stereotypical hanfu moves like silk and most xianxia characters end up rich enough for it)
most closures will be tied, buttoned or belted. hooks are plausible and so are clasps. zippers do not exist.
(unless you're in a modern setting where characters are regular people buying off taobao)
generally speaking, you only need to use another language's terminology when there is no english equivalent or there is a strong cultural nuance that would be missed. the latter is only true of hanfu when worn IRL, in the modern era, by real people (typically at graduations or weddings).
for more specific terms and insights on traditional chinese dress (hanfu & otherwise), i recommend checking out @ziseviolet and other dedicated chinese-by-chinese fashion bloggers.
if you've been hesitant to write in a historical chinese setting, i hope this post has reassured you that you don't need to learn pinyin to do it. it's scary to write a culture you're unused to! these tips are chinese-specific but the same logic broadly applies to all non-eurocentred cultures.
(the big exception is the names of people and places: don't translate these into english until you have a REALLY strong justification for it. even then, don't treat machine translation a being a reliable source when it really isn't.)
i am but one person with approximate knowledge of many things: these tips can help ENG writers keep readers immersed in CN settings. that's all.