Hold your picture up against the wall to determine where to place the picture wall hook. Mark this spot with a pencil.
Drill the appropriate-size hole for your toggle bolt through the wall at the pencil mark. For a 1/8-inch toggle, you'll need a 3/8-inch hole. Consult a toggle bolt chart to find the right size of hole for your bolt.
Push the bolt through the picture hanger. Thread the toggle on the end of the bolt, and spin the toggle until about eight bolt threads are showing in the back.
Hold the picture hanger in place in front of the hole. Push the toggle wings closed and shove the bolt into the hole in the wall to push the toggle through. Stop pushing when you hear or feel the wings of the toggle open up again.
Pull the wall hook toward you to create tension between the hook and the toggle inside the wall. Tighten the bolt with a screwdriver until the wall hook is flush against the wall.