To begin, cut 3 chains of different lengths for each earring. Here we've taken an average of 6cm for the longest. 

You can either use plain chains or incorporate a small rosary chain, as shown here. A great way to use up leftover chains!

Then connect the 3 chains on a 4mm ring.

Place a small dab of glue in the BO backing, then carefully place the cabochon. Be careful not to apply too much glue.

Finally, open a 3mm ring and connect the chains, the corrugated pendant and the BO bracket. Pay attention to the order of the elements: the chains must be behind the corrugated pendant.

Here you go! Beautiful creations ;-)