Lay a thread base, then tie in a tail of long, stiff brown hackle barbs at the bend - Catskill-long, a good shank-length. Using a couple of looser wraps so it doesn't flare; trim the long butts.
Tie in five or six peacock herls at the bend, catching them in a couple of inches up from the brittle tips; break or snip the tags.
Move the thread to the one-third point behind the eye and tie in two hen hackle tips with a pinch wrap; stand them up and post them with wraps at the base so they sit upright.
Optionally figure-eight a couple of wraps between the tips for a semi-spent set, and trim any barbs sticking forward so the collar stays clean.
Give the herls a couple of gentle twists together (not tight enough to break) and wrap a fat, chubby body from the tail to the back of the wings, watching the hook point; tie off and trim.
Tie in the brown dry-fly hackle behind the wings and wind two to three turns behind and three or four in front for a big bushy collar. It's what floats the fly and props the wings.
Tie off the hackle, pull everything back, build a small head, and whip finish, zig-zagging to avoid trapping fibers; snip or singe any trapped barbs and cement.