How do you arrange your books? 

“This man avoided putting books on the same shelf two books whose authors didn’t get on, even after their deaths“
“…for having criticised Cicero, Erasmus was sentenced by a Verona judge to pay one hundred crowns to the poor … Shakespeare and Marlowe both accused the other of plagiarism; Louis-Ferdinand Céline called Satre ‘a little shit- crammed piece of filth’; Jules Vallès considered Baudelaire a blusterer. As for Flaubert, he was a master of damming with faint praise: ’What a man Balzac would have been, had he known how to write?’ (The Girl who Reads on the Metro: Christine Féret-Fleury)

Mine simply have to live together peacefully or with resignation, assigned simply in alphabetical order. Others are more creative and place them by the order they read them in, size, genre, simply their colour or other more abstract themes. Click below for more ideas.
12 Clever Ways to Organise your book collection