I recommend checking a few of the thousands of boutique and niche clothing stories that populate the internet. These are not only home to a ton of interesting styles and fashion options, but they are often put together by passionate individuals or independent artists, and buying from them will support their cause.
The aboriginal clothing store found at https://shop.welcometocountry.com/collections/fashion is a good example of this, since it’s run by a non-profit. There are dozens of other similar stores out there, selling clothes made by native artists and meant to reflect the style and traditions of their cultures.
Another option is to simply look for stores selling clothes that match a certain theme that you feel suits your style. Whether it be clothing made to look gothic, metal, punk, high-class, or steampunk. Cyberpunk and other bolder styles have been gaining popularity lately.
You can also get something unique to you by commissioning clothes that either match your tastes or are made to reflect some aspect of you. Getting something custom-made is easier than ever these days, especially if the customization you’re after comes down to printing something unique on top of an otherwise mundane design. Getting entire pieces of clothing tailor-made for you is also possible, albeit more expensive.
Finally, you can get a lot of interesting styles by simply ordering from foreign stores, be it online or by traveling there. I already mentioned how you can get clothes from natives from all over the world online, but you can also order from local stores and artists from all over the world. Even stores that don’t have a website in English might be willing to ship internationally if you contact their customer support for help.
And keep exploring. The nature of the current globalized market makes it so that finding unique clothing comes down to figuring out the right keywords to use, so you never know when you’ll uncover more interesting options.