How to do it
Tie the yarn onto the small metal ring. Now wind the yarn packed tightly all the way around. Repeat this procedure on the large metal ring with a different colour yarn.
Place the small ring inside the large ring and tie the two rings together with one end of the yarn. Now start winding yarn around both rings all the way around as shown. Finish with a knot.
Crochet a string for hanging using chain stitches to the desired length. Tie this onto the mobile.