Anyone familiar with what I'll call the water knot? It's a simple knot used for tying climbing webbing or other "flat" rope, but I use it for round rope also. Use it for neck lanyards, necklaces (re-enacting using artificial sinue..a particularly slippery substance), etc. Holds tight regardless. Tie a simple loose overhand knot in one end of the cord. Take the other end and follow backwards through the overhand knot you just tied. Follow the other knot exactly leaving a small amount of cord exposed on each end. Pull tight!