If you are looking to physically find a book, this is what I do (1000+ books).
Whenever I buy a physical book or receive it in the mail, it gets entered into my library by the ISBN number (Library of Congress, listed on the back of every book). This is done by plugging in the ISBN's in "Import Books" under My Bookshelf in EYB. Each book so entered then gets a little Avery colored dot stick-um on the front page (yes, this book has been entered). Then it usually gets stacked on this 2 ft. pile to my right on the desk. When time allows, I go through the stack and decide if this is a baking book, celebrity, ethnic, ATK, etc. (often more than one description) volume. All that book is representing is entered under my Bookmark categories. The dot stick-um is also pencilled (not inked) in with shelf number. Each book is then physically placed on the appropriate shelf.
What shelves, you might ask? I recently gathered all the books from their numbered shelves in the family room, kitchen, under the bed, etc. and moved them into my new library. A large vacant bedroom was transformed with wall-to-wall black Billy shelves from Ikea. Each small shelf now has a small numbered stick-um so the shelf coordinates with my index. The dot inside the book is also marked to indicate which shelf it belongs to.
Now, to find all these books, I have added Bookmarks in my own account for which shelf holds which kind of book. IOW, for each book, I know the type (ethnic), the physical location (Shelf 31), the title (More Mexican...), and the author (Rick Bayless). All these descriptions are made for each book, so I can look up by any interest.
I do this with Kindle book as well, but that needs a print-out of the Cookbooks section of My Kindle at Amazon and I check off each one that is entered. The un-located or not-even-entered books stand out. I also have the small canvas collapsible boxes from Ikea that hold the special magazines...ATK specials, seasonal, my huge pile of NY Times cooking print-outs.
Yes, I am OCD. I think I spend more time organizing than I do cooking. But I am a fairly Happy Camper alone here during the pandemic, arranging books.