There are lots of "rules" out there about building a proper vingette, that detail how many items it should include, heights of the items, sizes of items, etc... But I think this all depends on the space in question, the style of the room, and type of items being displayed. I usually play it by ear and build each space as I go, but I do keep a few things in mind:
1. Use varying heights to create interest
2. Use different textures
3. Keep in mind that too many colors will start to look sloppy
With large built-ins like these, accessorizing can be a challenge. So I take it shelf-by-shelf.
I thought I would focus on the right side of the shelves to show you my process. I picked the shelf with some of my milk glass collection.
I began with one of my favorite pieces in this room, my chinese book ends that I found at a consignment store. The milky blue color was great for the room. I paired their subtle color with some brighter, complimentary-colored books that I own. My grandfather gave me his vintage gardening book a few months before he passed away. Those items pretty much took care of the left-hand side.
Then I went for a taller, more slender piece for some contrast.
Finally, I used an even shorter piece to round out the trio. You could say that I used the pretty standard vignette rules on this side of the shelf (three items, varying in size, similar style).
And this is the final product! By breaking up the shelf into two sections, I didn't get overwhelmed and also didn't under or over accessorize!