These are made using hand towels.
First, fold towel in half and move the front down so it hangs about 3 inches lower than the back. (You want more coverage in the front)
Next, find the center across the top on the fold and mark with a pin. Use another pin to mark 2 inches down.
Measure 2 7/8 inches from the center pin and mark. Do this on both sides.
So your pins should look like this:
Now your going to cut in a circular shape matching the pins.
Now it's time to cut some ribbing. Make sure you cut it so that it will stretch. Cut a strip 10inches by 2 1/2 inches, then serge (or zigzag) the raw edges together.
Fold in half, with your seam on the inside. Using four pins, mark the ribbing into equal 4ths.
Mark you opening the the towel into equal fourths as well. Then match your pins and pin into place, right sides together: (I put the seam on the ribbing in the back)