Here's an old tutorial we shot for a single limb/column tie. To be honest, I don't do it this way any more. I've updated it by adding a simple parcel knot (the first stage of tying your shoe laces!) before the final knot with the twist in it. The advantage of this is that it reduces the chances of the knot capsizing and turning into two half hitches, which can slip. I'm working on a proper set of tutorials that I hope to release later this year on DVD, which will go beyond the merely technical and show the ties in much greater detail. Knowing how to tie the knots is only a small part of the skill ;-)