My students weren't the only ones learning something during my micro macrame classes last weekend; I got some insight on the problems new knotters experience. We worked almost exclusively on the double half hitch (DHH) knot, and one of the most common issues was the knot ending up on the wrong cord - on the knotting cord instead of the holding cord. It's not always easy to tell that's happening unless you know what you're looking for, but it is easy to prevent.
Here's the trick:
Hope this is of some help to someone out there!