As a solitary, I am “self-initiated.” That’s pretty much the entire story. Pagans can (and have) sit around all day debating if that “counts” or not but you know what? Who cares? You walk the path, it’s what you are. So many churches squabble about little details, splinter off or try to annihilate each other. Do we really want to walk that line?
I did a formal ritual to initiate myself but I was practicing long before I did. Just like my marriage, I never felt I needed something “official” to declare my love to my husband or my gods. The paper’s nice and it comes with it’s perks, but without it, me and him would still be a loving couple and good parents. And I would still be a tree hugging, dirt worshiper. 😉