The concept is that the teeth go down over the nails, nails acting as a fulcrum, and torque created by your coat pushes the teeth against the wall, holding it all up.
Step 1: Materials
Step 2: Bending
Step 3: Installation
The photo below shows how I installed it onto a piece of wood, just to test it...I haven't put any on my walls yet. As you can see, this one easily supports my sweatshirt.