As a librarian, and especially as a cataloger, I have Feelings about the arrangement of books. However, one of those Feelings is that, in your own personal/household library, you should arrange your books in ways that make sense for you/your household. Part of that is going to depend what types of books you have, part on how much shelf space you have where, and part on how you use and look for your books.
In my household, we have several broad areas for books. General fiction is arranged alphabetically by author; books by the same author are alphabetical by title unless I can remember a series order easily or at least separate distinct series from one another. Anthologies are arranged alphabetically by title. Graphic novels and collections of comics are arranged by series, character, or title (depending on whether they're part of a series and/or how we would look for them).
Nonfiction books are organized by subject, with similar topics generally grouped together and flowing into each other in ways that made sense when I set up the shelves after we moved here. For example, one shelf has yoga/stretching -> massage -> first aid -> general science -> animals -> field guides for birds and plants -> pets -> art books (because we have some art books focused on different animals) -> biographies (because we have biographies of artists).
A few collections are separated out for various reasons. Picture books are in their own area because I had a small bookshelf with high enough shelves for them to fit in (mostly) comfortably. Cookbooks are on their own set of shelves in the kitchen, roughly grouped by topic or type of food (general, slow cooker, chocolate, bacon, etc.). Gaming books are organized by gaming system, then generally by title. Books on sex and sexuality, erotica, and NSFW graphic novels/comics are in the bedroom but otherwise mirror the organization of the main collection.
The guest bedroom has collections of miscellaneous information and short essays, as well as books that we have two copies of, so we don't mind if someone borrows them indefinitely.
This is very important research so I can figure out how to arrange my books