Start thread behind the eye; at the 70% mark stand a white poly-yarn post upright and anchor it with thread wraps up its base and figure-8s at the shank.
Run thread to the bend and tie in a few microfibbets, splayed, one shank length long.
Bind a stripped, soaked peacock quill at the bend and wrap it forward in touching turns to just behind the post. Half the overlap you think, so the body stays slim; tie off.
Tie in a dry hackle at the base of the post, then wind the working thread forward to just behind the eye.
Wind the hackle 4-5 turns down the post from top to bottom, parachute-style, and lock it at the shank in front; stacking the wraps downward keeps them from tangling.
Whip finish at the eye, passing under (not through) the parachute fibers, snip, and cement the head only.