1/3 books, 1/3 decor items and 1/3 open space is a good way to go. Many of your items are the same height allowing for no variation to draw interest - the eye has nothing to draw it around and through the shelves. Three of any one kind of item is sufficient. I see four baskets, 8 pictures or framed items; you get the idea. Are the shelves the same distance apart and can they be adjusted? You've done well to place the darker, visually "heavier" items on the bottom as an anchor, but you've overdone it with three baskets. You need a mix of tall and short, wide and narrow. Books can stand or lie down in stacks and can be used to elevate a short item. Rather than stringing the items across the shelf, group items in threes. A nice accent paint on the back of the shelves would add a lot to the vignettes you'll be creating.