There is no specific knot that you need to use when finishing stretch cord; an overhand knot will do. You may want to make a double knot for extra security. After you make the knot, you need to glue it with cement glue or clear nail polish to keep it secured. You can also place the knot in a bead before the glue dries out to make it stick to the bead.

I wouldn't advise it - knots in micro-fiber can be bulky. If you choose do knot, use a little clear glue to ensure it holds.