I make all my playlists by hand. I have three types:
Mixes that I’ve made, either as gifts or for myself; where the order is carefully chosen so one song leads into another pleadingly, where no one artist dominates the tracklist, usually with a specific mood or theme, like “cleaning” or “summer” or “breakup”. These kind of playlists are additive and creative; I start with an empty playlist then add and rearrange tracks until I’m happy.
“Best of” playlists that are every song I like of a genre or artist or local scene or year or music label. These are usually in release order, grouped by album; or sometimes in descending order of how much I like them (but still grouped by album). These kind of playlists are subtractive and reactive; I dump large swathes of the library in and then remove whatever I don’t like enough until only the cream is left.
Hemerographs, which is a word I made up to describe playlists where I’m picking songs one at a time and adding them to the queue, but I’m saving the whole queue to listen to again later to recreate the vibe of that day / party / activity. It’s additive like the mixes but more flow-of-consciousness and reactive; and also includes inputs from other people, since I’m usually making them on the fly in a social situation.