I have learned from Marie Kondo. I use many of her folding techniques to save space in cupboards. When I’m going on vacation, I use them as well to optimise my packing.
But there is an inherent problem with her teaching about books. She says you shouldn’t have more than 30 books in your house. But she also says you should throw away what doesn’t bring you happiness. All my books bring me happiness! Sometimes I just go and sit in my library and look at all my books and it makes me so happy! So thank you Marie, but I’ll be keeping my books. All 500+ of them!