So I found this rubber conveyor belt material on the side of the road, then I found old shoe insoles and some nylon webbing in my house, and glued them together to make sandals.
Step 1: Materials:
1. Thick rubber like the conveyor belt I found
2. Insoles (not shown)
3. Nylon webbing about 1" wide
4. Epoxy or similar glue
5. Heavy duty scissors
Step 2: Cut Out the Rubber
Trace out the shape of your feet on the rubber sheet. You might use the insoles as a pattern, or you might need to trim the insoles too. Use tin snips, heavy duty scissors, or a box cutter.
Step 3: Cut and Place Nylon Straps
1. Cut slits on the insoles between where your big toe and index toe go.
2. Pass a strap through here and back to your arch area.
3. I added another strap across the top. You can make yours as simple or complex as you want.
Step 4: Glue the Layers Together
Mix some epoxy and apply to the top of the rubber and the bottom of the insoles. Make sure the straps are in the right place. Clamp the layers together with tape and leave them to cure. Congratulations! You've just spent much more labor than is necessary to get something you could've picked up at Wal-mart for less than $2. But you're sticking it to the man by making your own things, plus these sandals probably won't break as much or give you cancer like the ones at Wal-mart.