Step #3:
Tie in the red floss on the far side of the hook with 3 wraps. Wrap the floss backward and forward with touching turns, making sure the floss lays flat and is untwisted. Stop just above the hook point. Then tie off and clip neat.
Step #4:
Tie in two crests for a fuller looking tail. Tail length can be personal preference but on fishing flies, I like mine a little long. Clip to the length of the first body section.