Step 1: Collect Tools & Materials
You will also need sheet metal and rivets or screws. I used the body from an old microwave that I got from freecycle. It's dirty and greasy, but that's perfectly fine with me. These garden planters are going to be outside holding soil anyway. It's not like I'm going to eat off it, per se.
The rest of the materials really depend on how you are going to mount, hang or attach the planters to a support structure. I used some old bits of cardboard, wood, pvc, conduit clamps to create legs for my three planters.
The tools I used are a hammer, rivet tool and rivets, a drill and various drill bits, C-clamps, an angle grinder with a cutoff wheel, tape and a permanent marker.