Finish the rug by following the cords through the knot, evening the loops out as you go until the knot is tight and even.
Take the short end of the cord, and the longer end and take them into the centre of the knot along the first line of the braid. The bits of the short cord you take out, will be replaced by the weaving in of the longer end.
Take both ends back to the underside of the rug (somewhere near the center), tie them together and trim the ends. Your rug is now finished.
If you are working on a full size rug, you can lash the the ends to the rug with quilting thread, buttonhole twist thread, or waxed linen cord to keep the ends in place and prevent them fraying.