This is one of the more expensive kitchen wall decorating ideas but one of my favorites and doesn't have to cost a lot if you shop wisely. Depending on your kitchen decorating scheme, you might want to add some iron grates, wooden columns or fancy metal architectural pieces to your walls. Just hang them up like pictures and they make a unique and unusual display. You can go with lacy metal pieces for Victorian or shabby chic décor (you can even paint them white or any color you want).