This might be a bit much for me to do, but in our library we seperate books by topic and not the Dewey Decilmal System. My idea was to make book ends that are topic based instead of using rather than putting unsightly labels on the shelves. By just looking at the bookend you can kind of tell what the shelf contains for book topics.

I spent an hour or so collecting junk steel and welding a tractor for the farming section of books. But i am thinking the other 10 topics or so might strain my time and creativity. i guess i could buy scrap iron themed bookends online though.

Either way, for the people with libraries, I pass on the metalworking idea.