Thank you for posing this question. This a tough question to answer directly and needs a nuanced understanding, as many people have different thoughts and beliefs about what is appropriation vs appreciation of Native culture.
What is cultural appropriation?
Cultural appropriation is the adoption or theft of icons, rituals, aesthetic standards, and behavior from one culture or subculture by another. It generally is applied when the subject culture is a minority culture or somehow subordinate in social, political, economic, or military status to the appropriating culture.
Why does cultural appropriation happen?
Cultural appropriation is a by-product of colonization, capitalism, oppression, and assimilation. In the case of cultural appropriation, culture is treated as a “natural resource” to extract from People of Color. Cultural appropriation is profitable. Objects and traditions (but not the people) of marginalized cultures are seen by the dominant culture as exotic, edgy, and desirable, which translates to profits.
Cultural appropriation is harmful because it is an extension of centuries of racism, genocide, and oppression. Cultural appropriation treats all aspects of marginalized cultures as free for the taking. This is the same rationale that has been, and still is, used to steal land and resources from Native people. Cultural appropriation of ceremonies and objects removes and distorts these traditions and things from their original contexts and into gross caricatures, with disregard for the history and present day reality of oppression.
I cannot give a list of “do not wear” or “do not purchase” items, but I can tell you that if you are wanting to purchase or wear an item, then I would suggest researching the design, the tribe and/or the artist and give credit to them. Try not to buy knock-offs, or tribal items and designs that are massed produced for the profit of a non-native company. Simon Moya-Smith created a list of 100 Ways to Support-Not Appropriate From-Native People, that is an extensive list of things to take into consideration.
Good luck on your exploration,