Start the thread at the front of the shank where the thorax will sit; the thorax takes only the front 25% of the shank. Tie in a length of Clear Midge Tubing at that point and bind it back to the bend.
Stretch the Clear Midge Tubing and wrap it back down the shank toward the bend, stretching hardest as you reach the bend. Then wrap it back forward over itself to the thorax point and capture the tag with thread.
Build up a small thread thorax over the tie-off.
Tie in a couple of strands of Blue Holographic Tinsel on top of the thorax for the back casing, and a single strip of red holographic Flashabou (or tinsel) along each side as side markers.
Wrap the thorax again with thread to smooth out any lumps from the tinsel tie-ins, then advance the thread to the eye.
Pull the Blue Holographic Tinsel casing over the top of the thorax and lash it down with two wraps at the eye, then do the same with each red side strip. Trim all the tag ends close.
X-wrap a bunch of White Antron in at the head for the gills, leaving it long for now, and whip finish.
Coat the entire fly with Loon UV Thick or Thin Fly Finish: apply it along the top, then spread it to the underside and all around the thorax with a bodkin. Cure with the UV light.
Pull the White Antron gills upright and trim them very short, just enough to show a spot of white at the front of the fly.