Knot one end of yarn to one D-ring.
Draw free end of yarn through second D-ring, leaving about 32 in. (81.5 cm) of yarn between rings. Knot yarn around second D-ring.
Draw end of yarn back through first D-ring leaving about 29-30 in. (74–76.5 cm) of yarn between rings. Knot yarn to first D-ring.
Continue to strand yarn back and forth between the D-rings, knotting alternately to the first and second D-ring and decreasing each length of yarn by about 2-3 in. (5-7.5 cm) from previous length, until all of the yarn has been used.
With pliers, attach a jump ring to each end of the chain, then attach each jump ring to a D-ring.