I've recently moved and really miss the great storage in my old house. However, it's given me an opportunity to creatively store my stuff.
I needed to utilize this bookshelf and wanted the clutter to be accessible but not visible.
I used this fabric covered frame (see instructions here)...
and my favorite crafting accessories, large binder clips...
and clipped them onto the upper shelf with about a 1/2 inch sticking out.
The frame sits on the binder clips and can be easily removed to access that shelf.
You can also use an open frame the same way to highlight objects. It's a fun way to add interest to your old bookshelves.