If the question really is "how does one become a shaman", then there is no definitive answer. Since the word "Shamanism" has come to be used as a descriptor for a wide variety of religious practices across a worldwide spectrum of cultures, the answer depends on the context in which you're speaking. Specifically, in regard to what culture's practices you're referring to.

That aside, I see no real distinction here between "Shamanism" and "Neoshamanism"... And I do believe that more attention to that distinction could seamlessly clear away much of the division in this discussion.

Given that many of us are speaking of Native-American influenced practices in the context of western spirituality, it should be noted when one is, in fact, referring to neoshamanic practice or indigenous shamanic tradition.

And, if one is speaking specifically in regard to neoshamanism, then it is important to note that neoshamanic practice claims no adherence to any traditional indigenous practice, and does not by default imply any requirement or prohibition of their appropriation.

Putting down a Neoshaman because they do not adhere to or respect indigenous shamanism is as ignorant and absurd as putting down a Buddhist for not adhering to traditional Hinduism, or a Christian for not practicing Judaism. :thumb_dow