Cut your piece of scrap closet rod so that it is 4 inches long. Drill three holes in a row down the length of the scrap rod. The two end holes are for your screws, the middle hole for your Super hook. Make sure the holes aren't too big for your screws and hook.
Line your scrap rod along the wall vertically, and mark the place on your wall where you'll be hanging your guitar hanger with your pencil. Make a line at the top of the hanger so that you don't lose your place, and also mark where the three holes on your scrap rod will be with your pencil.
Hammer a small starter hole in each of the three marks. Put your scrap rod back against the wall, and drill your two screws in the top and bottom of your scrap rod, starting with the top hole.
Twist the super hook into the middle hole of the scrap rod. Make sure the threads of the screw catch the wood. Once the super hook is screwed in, apply pressure to it to make sure it is stable.
Hang up your guitar, and enjoy the fruits of your labor!