Cover the shelf with contact paper to match it to the wall paper and the feel of the whole room. Position it  horizontally to transform it in to a bench. Add on the legs to give it some height and add in your storage boxes. Once that's done you can get a cushion on top to make it more comfy and last but not least add some pillows for decoration. 

Materials Used
Teal contact paper to wrap the shelf and the legs to totally transform the shelf.