a.) Group like things together.
b.) Odd number arrangements of objects looks great in a vignette.
c.) Turn a few books on their side.
d.) A bookcase doesn't always have to be about the books, add in a few unique objects and artwork.
e.) A little contrast goes a long way.
f.) Baskets or boxes do wonders. Hide all of that clutter.
Here are a few bookcases styled beautifully.