Here are some great shelf ideas. There is actually a very wide range of ideas you can use in the shelves in your house.
Featured is the “fishbone shelf”. I like how the zig-zag pattern contrasts with the horizontal and vertical lines of the wall and the way a house normally is.
You can rotate the shelves however you want, and make the best use of the angles in your house. Is this a nice example of modern Scandinavian interior design?