Ok Blip, I need you!

Trying to sort out my bookcase, but I'm not sure of the best way. HELP!

If I stack the books up & down I can fit more on, always a bonus. But (snigger, I said but) if I go left to right I can make them look neater & maybe double up. There's also the option of stacking them 2 deep.

(BTW although not diagnosed I DEFINITELY have OCD tendencies)

I think I may have answered my own question. Thanks Blip, you're awesome :-D