I think cultural appropriation is more a matter of having manners and considering the feelings of others. If you take something that is a meaningful to another culture and treat it as a novelty or turn it into a fashion statement you are doing cultural appropriation. You can avoid cultural appropriation simply by having respect for and learning about the culture/tradition you’re borrowing from.
Maybe, but surely you would agree it should be up to the appropriated culture to decide what is appropriate?
If a historically marginalized
group feels that you are appropriating their culture, the proper response is not to learn their history and then tell them that since you read a book it's now OK. It's to stop.
Most cultures have a wide variety of opinions. If someone wants to wear clothing associated with another culture, should they listen to the people saying "no, that's just for us", or the ones saying "we like seeing our ideas spread", or "of course, I'm happy to sell you this hat that I made in the traditional style"? In my experience, there will always be voices across that entire spectrum. If one always listens to the most restrictive ones, then it just makes everyone more isolated in their own bubbles.
I do think there are some areas where most people can agree that use of another culture's artifacts is in poor taste and not generally acceptable. A very specific example would be that members of a culture that conquered another culture shouldn't wear clothing or jewelry that was looted from the conquered people. I think most people would agree that that crosses a line. Same for costumes that trivialize or mock another culture, like children playing cowboys and "Indians" in the 20th century, or minstrel shows. But outside of that core, I think it turns into a grey area very quickly.
It's a really tough problem to find a good answer to, and IMO it's impossible to find one that makes everyone happy because of that diversity of opinions in nearly every culture.
I agree that it should be up to the appropriated culture. I’m not saying all you have to do is read a book. If you want to participate in another culture it takes a lot of work to learn and participate respectfully. And you’d probably have to do it up front rather than after the fact to justify yourself.
For example: Eminem is respected as a rap artist because he apprenticed himself to the culture and celebrates it. He didn’t just try to make money off rap and learn a bit of history about it to justify doing so.