Agree with everything except the oil. I use Avocado a lot for cooking but not on a brand new pan. I've certainly tried to season with it specifically when I was new, but find it flaky and cumbersome.

I find fatty meats(bacon, sausage) or just canned lard to work absolutely best for seasoning. It's also what our ancestors used before they probably even knew what an avocado was. For a vegan, I'd assume shortening is ok as well, but I've never actually tested that.