This is what we did with a closet in our Cape Cod house - a closet built into the side of a dormer. Shelves are 12" wide. The back shelf is 24" deep and about 40" wide total - enough for large plastic storage bins. We added woven baskets on the shelves in a light color and will also add tags.
This actually might be a good idea to use for my closet in the office. Let the rod go all the way to the right but put shelves on the left...hmmm I am always looking for ways to make my closets work better for me.