Plan the location of your old plates on your wall. Mark the locations where you want them to hang by making a small X with a pencil.
Install a wire plate hanger at each planned location for the old plates. This gives the appearance that the plates are suspended directly on the wall. Use a drill to make a starter hole in the wall if necessary. Screw the plate hangers into place.
Snap one old plate into each wire plate hanger to complete your decorative display.