Flip flops are the best and easiest form of footwear. They are perfect for the beach, hanging by the pool or summer days. You can also wear them around the house if you want some kind of footwear but not a full shoe or slipper. Flip flops are easy to make and you can customize them any way you want.
Take a piece of cardboard and place your foot on it. Loosely trace around your foot, leaving about 1/2" extra all the way around. Repeat and trace the other foot in the same manner. Cut out the foot outlines.
Cover a table or flat surface with cardboard or other protective material. Place a sheet of foam on it. Put one of the cardboard foot outlines on top of the foam. Trace the outline with a pencil. Take off the cardboard cut out. Use a razor blade and carefully cut along the outline and down into the foam. Take your time to make sure your cuts are clean and smooth. Repeat with the other piece of foam and other cardboard foot cut out.
Place your feet on the foam cut outs. With a pencil, mark the spot between your big toe and second toe where the flip flop strap should go. Then, mark the spots on either side of the foot where the straps will end, typically near the middle of the foot. Repeat on the other foam foot.
With your pencil poke a hole through all the three spots you marked on each piece of foam. Take your plastic cord and measure it from the center toe hole to the side hole. Cut a piece this size. Then cut three more of the same length.
Plug in your hot glue gun, place a hot glue stick in the gun, and allow it to warm up. Fill the center toe hole with hot glue. Place two piece of plastic cording into the hole. Put a little bit of hot glue between these two cords at their lowest point close to the foam. Press these cords together and hold for ten seconds. Fill the two side holes with glue and stuff the other ends of the cords in these. Allow to dry for a minute. Flip the foam flip flop over. Fill the holes with hot glue and wipe flat so the glue fills the hole but doesn't overflow. Allow to dry. Repeat on the other flip flop.
Choose a color that won't get dirty easily so they will stay clean longer.
Be careful when cutting the foam not to poke it or you will create unnecessary holes.