Seasonally, usually one day of the week I spent some time sorting through all the screenshots I've taken so far; moving them to their respective folders or stitching them and then moving them.
I don't. I basically only save lewd screencaps, which are fine just staying in a folder for that series. I do also on rare occasions take a screenshot of a joke or reference or such that I don't want to forget where I saw it, but I have few enough of those that they are best just clumped together in a single folder.
I don't. Not really. For Waterfox screenshots, they just get dumped into my downloads folder, so those are basically lost in hell if and until I find them to put them somewhere better. For anime and stuff, I have MPV shoot out screenshots into a dedicated folder, and animations into another.