I have a TBO (to be organized) folder where I dump things that I can't clearly categorize right away. Eventually, I spend a few hours sorting everything manually. I sort my music by genre, not by artist or year, so when im in the mood for say, some DnB, I don't have to recall the artist or album, I just hit shuffle on my DnB folder
I don't rely on auto-taggers, because I discover artists from soundcloud and YouTube that may not have their info readily available on such websites.