Lay a smooth orange underbody from behind the eye to the bend; the hot orange glows through the body and is the whole point of the fly.
Tie in a length of amber/brown D-Rib by its tip at the bend, flat side down.
Wind the D-Rib forward in touching turns to the 75% mark to form a segmented, translucent shell over the orange, and tie off.
Tie in a ginger rooster hackle and palmer it back over the body in open turns, then counter-secure it. Trim the fibers short and ragged to mimic the tattered barbules of a stripped quill.
Tie in a grizzly hen hackle by the tip and take 2 turns as a soft leg collar, sweeping fibers rearward.