Here are the basics:
You will need your cord and the hex nuts. I used 16 nuts, but you can use more or less depending on how you want it to look.
Cut 2 lengths of cord, one 80cm and the other 40cm. Double the longest one over giving yourself a loop at the top. Using the shorter one tie a knot about 5cm down from this.
Once secured you can start braiding the three strands (you can loop the end around something unmoving, this will give you more stability whilst you braid).
Start adding your hex nuts whenever you like, I did mine about 5cm down the braid. When you are about to take a strand from the side and cross it over, add a nut.
Keep going to your desired length, then finish of with some more braiding.
At the end of this braid tie it in a knot (do not cut off the end bits yet). Now you just need to finish it off to make it look neat.
Using thread and a needle, stitch the strong thread through the beginning of th braid and wrap it around until you have just enough of your loop left to go over the knot at the end.
At the knot end sew your thread around it making sure that it will not unravel.
Then trim the excess threads off the end and you are all done!
I also made one with some thinner cord and using brass washers and beads. I actually prefer this one!