Basic technique for jewellery making: this is the way to make a knot in your elastic cord
You will need a firm knot in your elastic cord to secure your work. Start with a single knot. When you make the second knot on top of the first one, don’t pull your thread once but twice through the loop to strengthen your knot. Fix your knot with a drop of glue and only cut the loose ends when the glue is dry.