I recently deleted a bunch of old kits that I know I'll never use but I kept the stuff from like Libby and La and Dani Mogstad that I love and just can't part with
however I have all my folders stolen down by themes (fall, Christmas, all boy, Halloween, everyday, etc) so every time I move something from my downloads folder (something new I have bought) and put it in its perspective folder, I skim through that folder and try to delete at least one kit that I know I will never use again