For a long time, one particular idea was associated for me with bookends: if you have to put metal horse heads on your bookshelf, you simply don't have enough books. Not having enough books can, of course, be caused by various reasons, but I my opinion none of these reasons were excusable. I was able to overcome this feeling, mainly due to acknowledging the fact that a home library differs from any other kind of library - it must feature certain design elements that turn it into a living space of a special kind. It is interesting then that bookends are somewhat unique, in a sense that they are designed specifically for the needs of home library owners. Why not use them?
One practical advice that you should keep in mind. Because bookends vary in style and material, you should choose at least the material that you are going to use for most of your bookshelves. For example, it is easy to go with brass or cast iron. This way you will always be able to add more bookends, even if it is impossible to find the exact matches for your existing ones.
Bookends on Amazon