Put your thread through a seed bead going in opposite directions, then add a seed bead to each thread, and again put the thread through a seed bead going in opposite directions.
Add a bicone bead onto each thread.
Add 4 seed beads to one of the threads, and take the end of that thread and put it through the first seed bead. Pull that until it's at the bicone bead.
Add another bicone bead to that thread, and add a seed bead with the treads going through in opposite directions.
Repeat these steps alternating which side you add the 4 seed beads to until you have the length you want.