I prefer size as well. As a HUGE consumer of pillow covers (I love fabrics from India and have used pillow cushions all over my house to reflect that) I first search by size, then browse the various colors and patterns available in the size I need- you are right, usually I pick pillow covers to cover throw or other pillows that I already have since my couch is made without attached cushions and has just a wide array of throw pillows from gigantic to small on it. I love the way yours is already organized and your covers are very nice, by the way.