Head: Small or extra small pearl glass bead or nickel tungsten bead
Thorax: Rainbow scud dubbing from Wapsi or Hareline
Wingcase: Large, pearl Mylar
Abdomen: Large, pearl Mylar wrapped over red thread (try other colors like red and black holo)
Tail: 4—8 pheasant tail fibers
Hook: #14—#20 Tiemco 2457, Daichi 1150, Mustad 80200br, Dia-Riki 135
Thread: Uni 8/0 red, UTC 70 red
1. Start thread near the bend of the hook. Remove 4—8 fibers from a pheasant tail center feather and tie them in 1/2 way around the bend of the hook. Make sure to leave only 1—2 mm of tail fibers out for the tail.
2. Tie in a 3-inch piece of Mylar where the tail begins. Wrap a thin thread body 3/4 the distance to the eye of the hook. Wrap the Mylar forward, over the thread body. Tie off the Mylar about 2 mm away from the beadhead. Pull the Mylar back towards the tail and secure it with a few wraps of thread.
3. Use Rainbow Sow Scud dubbing to create a thorax in the space left open between the Mylar body and the beadhead. Make the thorax 1 1/2 times larger than the beadhead. Wrap the dubbing forward to close the gap between the body and the beadhead.
4. Pull the Mylar over the top of the thorax and tie in directly behind the beadhead. This will create a wingcase. Tie off the Mylar with a half-hitch and whip finish the fly. Make sure to pull the thread snug to hide the whip finish behind the bead.
Here's a video from Fly Tying 123 that provides a great "how to".