Form, function and simplicity, what more could you want out of a fly pattern? Other than the hook and the thread, the fly's name is the materials list, CDC and elk or deer hair. I believe the effectiveness of the fly is due, in large part, to the CDC which traps small air bubbles that not only help the fly to float but also make it look extremely realistic.
If I could only tie this fly in one size, it would absolutely be a 16. So I'm going to tie it here on a Dai-Riki size 16 #305 dry fly hook. With your hook firmly secured in the vise, start the thread just behind the hook eye and wind all the way back to the hook bend. Here I'm using UTC 70 and the color is brown. I've also selected a single brown CDC feather with its longest fibers about 2 hook shank lengths. Holding the feather in your left hand, pull the fibers forward to the tip with your right and then regrasp with your left. Place the feather tip on top of the hook shank and take 2 wraps around the feather and the shank. Then lift the feather tip slightly and take 1 wrap between it and the hook shank. Another wrap around feather and shank and the slippery CDC is locked into place. Now wind your tying thread up the shank to just behind the eye.
With hackle pliers, grab the stem butt and begin making adjacent wraps up the shank. Keep the feathers straight, there's no need to twist it as you go. Once you get to about the halfway point on the shank, you should notice that you've begun wrapping free fibers around the shank. Use your thumb and index finger of your left hand to pull these back as you wrap. Continue making wraps with the CDC to just behind the eye and then tie off the stem with two good secure wraps. Remember CDC can be a little slippery. Snip the stem butt off close to the wraps and then take another nice firm wrap for insurance. Now you're ready for the wing.
Select a small clump of finely tipped elk or deer hair in the desired color, here I'm using natural, and snip it free from the hide. With your fingers or a fine-toothed comb, remove the under fur from the base of the hairs. Then, using a hair stacker, stack the bundle to align the tips. Measure the hair on the hook making sure the tips extend only to the outside of the bend. Keeping that measurement, pass the bundle to the thumb and index finger of your left hand and snip the butts off right at your fingertips. Place the bundle on top of the hook so that the snipped butt ends are aligned with the very front of the eye. Make one and a half turns of tying thread around the bundle and the hook, pulling straight up with good tension at the end. Then bring the thread around to complete the second wrap. Next, bring the thread through the butt ends at a 45 degree angle. Working it down and in really helps to lock the bundle in place. With that done, lift the butt slightly and make a couple of tight wraps between them and the hook shank. You can then whip finish the fly with about 3 or 4 turns. And finally, cut the tying thread free.
A small drop of head cement on the underside of the wraps will help to keep everything where it needs to be. It's hard to find a situation where this fly won't work. And I suggest everyone give it a try.