Doing it by the book
If your book collection is threatening to take over every last inch of your shelving, perhaps it is time for a major review of how you display your tomes.
Start by emptying your shelves. It's easier to figure out what you want to do with them when you have a blank slate.
Remove the books you no longer want and donate them to local charities. This will help your shelves remain clutter-free and leave space for new books you really do want to read.
Decide how you want to categorise. Popular choices should be in alphabetical order, by author or title, or by genre.
Alphabetical listings are the most obvious organisational method, and probably the most reliable. You can follow the library system and arrange by the author's last name, or by title. Remember 'the' and 'a' don't count. After they are organised, be sure to double-check to make sure they are in the correct order.
If you have lots of different types of books, it may be easier to arrange by genre, such as fiction, non-fiction, literature, biographies, coffee table books, or whatever it is you're interested in.
As long as the categories make sense to you, the system will work. Art and design books can be organised chronologically so that sections start with ancient Greece, progressing to the Middle Ages, the Renaissance, the 18th century and then by artistic movement.
Other options are to organise by height and colour, although it may take a little extra work.
It is also possible to arrange according to colour. This is a controversial system among book lovers who argue this makes it more difficult to find what you are looking for.
But if you don't need access to particular books all of the time, or if you can easily identify your books by their spine colour, then this could be for you.
Options include arranging them in colour blocks or chromatically across a whole bookshelf.
If you prefer a more neutral look and have the time, try covering all of your books with plain paper, or other wrapping so they are all the same colour.
Unless they really are just for show, you could arrange them in some sort of order and perhaps label them neatly in white ink.
After doing this, try putting smaller books at the top and bigger ones at the bottom and keep those that are similar-sized together.
Try to cull ragged books, especially paperbacks, and leave a little breathing space on each shelf.
Put your most attractive books at eye level and keep them straight up and down or horizontal.
If you keep some books upright and others stacked, it allows for books to act as bookends for one another and provides a few flat spots for displaying favourite objects. Stacks are physically better for the books, so this is something to consider if you have old or rare items.