Never throw out your old books, especially if they are leather bound! Just remove the dust jacket (if there is any), assemble them in assorted sizes and colours depending in the length and design of your shelves. Then grab some cheap acrylic paint and any brush, paint a motif of your choice (never hurts to doodle the idea before starting to paint) on the spines and if you wish even on the covers of the outer books. Make sure to have the line up held tight and steady for the continuity. Just like that you’ve remade some of your old and unwanted pieces of literature (is there even such thing?) into classy looking and uniquely designed decorative pieces for your household! And if you don’t read (shame on you!) and still want it to look as if you have put that head of yours to some serious intellectual use, there are always old neighbours or vintage book markets to turn to for some cheap but beautiful bricks.