There are a couple important things to understand here. One of the most important is that there is a different between cultural interchange and cultural appropriation, but more on that later. Another important thing to understand is that context matters. There's a tendency to believe that behaviors divorced of context should have an intrinsic morality or be associated with other intrinsic qualities such as whether the behaviors should or should not be engaged in, whether they help or hurt people, etc. But this is a fantasy, and one born of privilege as well (the privilege to ignore the oppressed, ignore context, etc.) We cannot ignore the context of centuries of exploitative and racist colonization and empire. A straightforward classic example is the swastika, an ancient religious symbol that has been forever tainted due to history.
We cannot pretend that we live in a world where everyone is on an equal playing field and where all of the crimes and iniquities of colonialism and empire have been erased and smoothed away. For that reason those who belong to cultures on the higher end of the privilege spectrum need to tread much more carefully when they "borrow" and "explore" elements from other cultures. Because the pre-existing power imbalances at play can cause cultural exchanges to magnify the power imbalances. For example, someone from a wealthy culture can more easily market and merchandise cultural elements from a poorer culture, funneling money to themselves by selling the culture of others.
Another thing that's worth pointing out here is that a legacy of trauma and tragedy can preclude even otherwise benign or even beneficial activities from having benign or beneficial effects. Bad acts hurt people, they hurt relationships, they hurt societies. Think about someone with PTSD who has a hard time accepting love from others. The act itself (expression of compassion from a friend, for example) may be perfectly benign in the abstract, but within a context of surviving trauma it may even have a harmful effect. People coming from a background of privilege may be unfamiliar with the notion of having things in their life that have been ruined by actions of previous generations creating ongoing systemic problems, but it is nevertheless a very real phenomenon that billions of people are familiar with. Yes, it's a bit tragic that we have to be more careful with cultural interchange than we really ought to be but that tragedy has been imposed by a legacy that has included not just exploitation, theft, and slavery but also genocide. So tread lightly and thoughtfully.
Now, as to cultural appreciation, the natural (and beneficial) aspect of cultural "borrowing" and mixing vs. cultural appropriation. There is a difference and it is possible to navigate cultural exchange without falling into the trap of appropriation. For one, ask yourself whether there is anything monetary going on, are you packaging up cultural works to sell outside of that culture? Are you financially benefiting from appealing to interest in a culture that is not your own? That's more likely to be appropriation. Is your "borrowing" or enjoyment of a culture heartfelt, authentic, and respectful? That's more likely to be simple cultural appreciation and interchange. Is your representation of aspects of a culture a caricature, does it draw on narratives of "exoticism" or "savagery"? That's likely to be appropriation. Does it encourage people to find out more about the culture in question, does it seem like a celebration of the culture? That's less likely to be appropriation.
And so on. There's no rule book, all of this requires understanding why cultural appropriation is problematic, it requires understanding the history at play and it requires being thoughtful and understanding when exploring other cultures. A simple first order test is just to consider whether or not there is a power or wealth imbalance between the cultures in question and whether or not the particular activity amplifies or enforces that imbalance or not.