This is an instructables that is very easy to make. First, you need scissors, marker, string, and cardboard. Second, cut out the shape of your sandal, mark the holes on them and put holes in them. Third, use some string(length depends on your feet) and put them through the two holes near the bottom and tie a knot. Fourth, put the two other ends into the one hole on top and tie a big knot with the two strings. Fifth, just cut off the excess string.