Made using a Japanese art called Kumihimo.
I make lots of bracelets, anklets, necklaces, keyrings, cords using this and other knotting techniques.
Using a disc like in the picture set up the threads according to the pattern, then take the thread on the right by the start and take it down to the bottom on the right. Next take the one on the left of the group of three you have made and bring it up to the left of the thread on its own. Rotate counter-clockwise and repeat.