If you would like to transform an empty wall into something useful then you can search for every kind of knobs.
The knobs change their role! They are getting braced on the wall and they replace the common hanger. Try to find different pieces, colorful and as distinguishable as you can. Put them on the wall in an asymmetrical position or on a piece of wood, vertical or horizontal and create an unusual composition that it is going, not only, to decorate your wall but it will also be very practical and it will give particularity to the whole surface.
Steal ideas and make your imaginary creation.