Measure the fabric to create a toga. You will need two rectangles of white fabric that are 50 percent wider than you are and as long as you are tall. For example, if you are 5-foot-6 and 38 inches around at your widest point, your fabric needs to be at 5-foot-6-inches long and 27-inches wide. Calculate the width by taking your widest measurement, dividing it by two and adding half of that number back. If you want to add purple fabric, choose a thin fabric that is 3 to 4 yards long.
Assemble your toga. Sew two straight lines, one on each side. Leave an opening at the top for armholes and pin the shoulder. See the illustration for directions on sewing the toga. The purple fabric can be draped over your shoulder, or you can pin it to the shoulders when you pin the top of the costume together.
Make a wreath out of your craft store vine to place on your head. This is done by making a circle with the vine and weaving the vine around that original circle. You will only need to use a couple of feet of vine so that it does not become too bulky.
Put on your Greek goddess costume. If you have pre-pinned the shoulders, put it on like any regular dress. Once you have the dress on, take your gold cording and wrap it around your torso below the breasts, making an "X" in the front of your body and also wrapping it around your waist. Put your wreath on your head and your costume is complete.