How do you organize your e-reader?

I'm curious as to how everyone organizes their e-reader because my Kindle is an absolute mess right now. When I first got my Kindle I made separate collections for each genre and organized my ebooks into those collections. That didn't really work all that well because then I would forget that I had certain books. Right now I have collections for:

 

  • Genres
  • By series (just for those series that I really enjoyed, otherwise they go under their genre)
  • To read-near future
  • To read-someday
  • Netgalley-read

 

 

And then of couse I have some books that aren't in any collections yet, just floating around until I can find a collection to put them in (Most of them are Netgalley books that I haven't read yet). I wish I could put a collection inside of a collection that would probably help me out. Recently I tried to clean out my kindle a bit by deleting books off of it that I have either already read and don't feel like keeping on it or don't want to read, and that helped a bit. So everyone out there that has an e-reader how do you organize your e-books?