Put a size 12 standard-length barbless dry fly hook in the vise and start olive thread, waxing it lightly.
Spin bright green dubbing on and wrap a distinct little bulb at the very butt for the egg sack; if you are going to the trouble of an egg sack, make it prominent.
Take the thread up front and catch in two strands of Peacock Herl, then wind the thread back to about midway and leave it hanging there so it can trap the herls if they spread on you.
Wrap the two herls forward to where the wing will sit, just past the egg sack end of the body, and tie them off.
Stack a small tuft of dun-coloured deer hair and measure it a little past the bend, just past the egg sack.
Spin the thread clockwise to cord it up and take several firm wraps to set the wing; the butts will flare and that is fine.
Trim the flared butts off before you release the hair, because the moment you let go the wing springs up and makes trimming awkward.
Let go, take a couple of medium wraps rearward to lay the wing down, then tighter wraps forward, and sculpt the butt stubs flat with small scissors.
Throw a few loose wraps, leave the thread at the back of the head and tie in the dun dry fly hackle, running the stem forward under the wraps to minimise a lump.
Take three full wraps of hackle; four would be bushier than you need with a deer hair wing already floating the fly. Snip the excess.
Pull the barbs back just enough to make room without sweeping them, whip finish with a slight zigzag so no forward-pointing hairs get trapped, tidy any strays and add a drop of head cement.