Lay a black thread base from behind the eye all the way back to the start of the bend on a size 6 2x-long streamer hook.
Take a clump of green Squirrel tail from the side of the tail (those hairs are longer and show the green-black-green banding), stack it, and tie it in as a tail a little longer than the hook gap. Two medium wraps, check the length, then a tight wrap. Take a wrap under the tail so it does not point downward.
Do not snip the squirrel butts. Bind them forward as an even, flat underbody the full length of the shank and snip them where the head will be. Squirrel tail lies flat and does not flare like deer or elk.
Tie in the medium Dark wire Rib, laying it parallel along your side of the shank to keep the body level, and wind the thread all the way back. Two tight wraps at the rear, then back the thread up slightly to leave room for the tinsel.
Catch in size 14 Silver Mylar tinsel at the rear with the silver side down so silver shows when it is wrapped, using as little material as possible. Take the thread forward in open wraps, keeping it flat so it does not disturb the body.
Wrap the tinsel forward, each turn slightly overlapping the last. The first turn may need to go completely around to hide the black thread at the rear. Tie off at the front and snip.
Counter-wrap the Rib: one full turn at the rear, then evenly spaced, fairly tight turns forward to lock the tinsel down. Catch it off with two tight wraps, spin the wire off, and bury any sharp point with a couple of loose wraps.
Pull a fair-sized tuft of White marabou, break the tips off to length, and snip it from the stem so there is little fluff in the way. Flip the fly, judge the length with a couple of wraps, lock it in with a tight wrap or two as the Throat, and snip the fluff.
Select two Indian saddle feathers, badger, with a strong dark lateral stripe. Line up the tips, strip the stems to the wing length you want, and pull a few extra barbs off the bottom so they lie flat. Set them on top with two or three loose wraps, confirm they are coming off the top in the plane of the hook, then tighten.
Let the stems bend around the curve of the head rather than snipping them high, so the head has no step. Whip finish with three or four turns, snip the thread, and coat the head with UV resin or varnish.