First thing to note here is the use of a textured wallpaper for the background. This particular grasscloth has an organic feel to it, making it a good background for this client's collection. By covering most of the books with white paper, the more important books stood out, along with the various glass accessories.
After taking your background into consideration, look at what you have the most of, possibly books, and hopscotch them on alternating shelves from left to right. Try placing the books in horizontal and vertical positions. If your collection is another object, like vases for example, the same principle would apply.
If you are adding additional hidden storage (and decorative boxes are a popular item right now), make sure they are consistent in look or feel. Use similar finishes or colors so it doesn't look cluttered.
Notice the collection of metal owls on the shelves in the first picture, we call that a "graphic grouping", since they are "like" items. By combining the collection you will get more of a visual impact. The same idea was done with the vases in the top shelf.
Winter is a great time to look over those neglected bookcases! Go ahead, take everything off those shelves and start "restyling"!