Mount a size 18 dry fly hook with enough purchase in the jaws that it will not fly out, and lay a yellow 12/0 thread base back to the start of the bend.
Tie in a grizzly dry fly hackle at the bend for the rear hackle. It should be slightly longer in the barb than the front hackle, at least one and a half hook gaps. And take the thread forward to about the hook point, parking it with three open wraps.
Wrap the rear hackle three or four turns forward to the hook point, unwind the three parking wraps, and tie the hackle off with three tight wraps; save the leftover feather for the front hackle.
Wax the thread and spin on a very thin, short noodle of yellow rabbit dubbing (underfur from a yellow Zonker strip works).
Dub a slim body forward from the hackle tie-off to about the 75% point, keeping it thin. The body is only there to give the fly color.
Stack a small tuft of fine natural deer hair, measure it just past the bend of the hook, and set it in with a pinch wrap and a second wrap; take the thread a little farther back to leave room for the front hackle, then trim the butts.
Take a few wraps over the butt ends to flatten the area so the front hackle wraps cleanly.
Tie in the reserved grizzly hackle with three or four tight wraps and take four or five turns in front of the wing with hackle pliers, keeping clear of the eye.
Tie the hackle off, snip the tip, stroke everything back and build a small head.
Whip finish and add the smallest drop of head cement, keeping it out of the eye.