Wow, I just realized I have like three dozen or less paper books, everything else is electronic.
I would start with a section of frequently used books, alpha by author.
Next I would sort into fiction and non-fiction and then group within. If there's cross-over, group them together in subgroups - for example, if you have both non-fiction books on, say, French history and novels based on French history, you'd have a large group of French History that would start with the non-fiction alpha by author and then the fiction, alpha by author or title (whichever works best for you). If you have a large enough group - say, 30 books about World War II, you could break them further into sub-groups: books about the Euro theater in one group, books about the Pacific theater in another.
no subject
I would start with a section of frequently used books, alpha by author.
Next I would sort into fiction and non-fiction and then group within. If there's cross-over, group them together in subgroups - for example, if you have both non-fiction books on, say, French history and novels based on French history, you'd have a large group of French History that would start with the non-fiction alpha by author and then the fiction, alpha by author or title (whichever works best for you). If you have a large enough group - say, 30 books about World War II, you could break them further into sub-groups: books about the Euro theater in one group, books about the Pacific theater in another.