Uh... chunks? I suppose academic/studies books are in their own area & ordered by title, unless they're oversized & need to be put elsewhere. As we don't want our fantasy novels mixing with our religious studies books when we need those, lol. Fantasy & that general genre are then sorted by title, barring oddities. Art books only go with art books in a seperate area, as all of them tend to be oversized & tall or too long. I guess whatever can fit whatever. We have such a huge variety of books that a lot of it currently is hugely disorganized & shelves are sagging under the weight. I never sort by author because my memory is poor & we rarely have anything by the same author, or like- I don't want Vyasa (Mahābhārata) to be at the end of the shelf if I sorted by author? Dunno we're a mess due to my partner & I mixing academic books with stuff like Battletech novels. Alphabetical is about the best we can get.