Since you mentioned the topic of Buffy's outfits, which ones did you like the most?
This question brought an absolute flood of mental images to the surface, I tell you what. Unfortunately most of them were of the outfits I hated, which was most of them, because even when it was airing I did not like Buffy’s outfits much and they have not aged well.
I guess the dress she wore in Restless is good? And I remember liking her red top with the drapey neck in Once More With Feeling.
Aside from its strategic use of leather pants, though, the costuming on Buffy was... kind of frustrating for me, I guess? There were some super iconic villain outfits (Spike’s red shirt/black coat, Drusilla’s white dresses) and outfits intended for specific visual impact (Buffy’s Prophecy Girl dress, Cordelia’s ice blue brocade in The Wish), and as mentioned, I do applaud their strategic use of leather pants as visual shorthand.
But I don’t think they did a great job of using costume to show character growth, especially for Willow and Buffy. Buffy was always a fashion plate, but her outfits were kind of all over the place in terms of conveying her actual personality.
And I can kind of see what they were trying to do with Willow, I just don’t agree with it. Willow went from very deliberately plain/dowdy in S1/2, to a mix of aggressively cutesy (Dopplegangland) and baby Wicca looks in S3, to this like. VERY 70s thing in S4 with lots of maxiskirts and corduroy and that big old shearling coat. but past S3 none of it really read to me as things Willow would actually choose for herself to wear, somehow?
I think I just prefer costuming that gives characters a more deliberate, developed aesthetic, and Buffy didn’t do as much of that for the main characters.