How do you organize your library and/or bookshelves?

I bought a new small bookcase today to go behind my chair so I can reach stuff easily, which makes seven bookcases in this office.  You know, the build it yourself fake Carolina oak from Office Depot, but looks surprisingly good with my antique oak desk.  Good enough that I wouldn’t mind ditching my other cheap bookshelves and replacing with these cheap bookshelves just to have it all match-ish.

But here is the problem.  Organization.  My bookcases are fairly organized, but they constantly annoy me.  For example, I want all my British mysteries on one shelf, but they don’t all fit.  I want all my Celtic history on one shelf, but it doesn’t all fit.  All my Regency research on one shelf, but… right.

One thing I did with the novels that I don’t mind having out of sight is buy these things.

That one holds all my British mysteries. (Almost. As usual, it’s crammed full and yet I managed to turn up a few more this week.)  I also have these open-topped ones for other book collections:

And a green one, too.  (I like color. What?)  It’s not that they look Home Beautiful (they don’t) but just that they hold similar-type books in one collection that otherwise wouldn’t fit on one shelf.

And even so, stuff isn’t very organized.

What do you do? How do your organize your books? I have a new bookcase and I wanted all my “at my fingertip” writing resources on the top shelf and–they don’t quite fit.

The story of my life!

[I must say, my Kindle makes it easy to organize my e-books. One book can show up in several collections–by author, by type, by historical time period, however many different classifications I want to use. Sweet.]