Ron Hazelton shows the most secure way to hang heavy mirrors or art on plaster walls using toggle bolts. Attach a sturdy hanging wire to the piece if necessary. Draw a level line on the wall where the top of the piece will go. Stretch the hanging wire taut and measure the distance between the wire and the top of the frame. A two-bolt system will keep the piece level. Drill two holes this distance below the wall line. Using masking tape prevents the plaster from chipping. Fold the toggle wings and insert the bolts, then tighten. Hang the piece on the hooks, then enjoy.