Discussion: How Do You Organize Your Bookshelves?

Hi, everyone! Currently I'm trying to redo my bookshelves, and I was wondering how other people organize their shelves. I've seen people organize multiple ways.

By author. 

I think the most popular way to have the shelves organized.

By genre. 

At one point I did this.

By color. 

I think this is a really pretty way to have your shelves!

Also, do you add decorations to your shelf? Like funko pops, candles, postcards, etc.

And I'm sure there are more ways people organize their shelves. Personally, because I have too many books and not enough shelves, my books are pretty much just shoved anywhere on the shelf there's room. I try to keep all the books by one author together, and I keep all my library books in a milk crate (Which was my Mom's idea, and I love how it keeps them all together! Plus, I think it looks good.). But that's about the end of how I organize my shelves. I would love to have lots of bookshelves eventually, and to be able to organize them better, but I'm happy with how they look right now! I add decorations to my shelf, too!

Once I'm finished with redoing my shelves, I'll instagram a photo of they look.

How do you organize your bookshelves? Tell me! I would love to know. :)