This is a size 18 dry fly that borrows much from the venerable Hornberg. Although it's usable year round, I've found it especially effective in the fall when small colored-up wild fish are on the move. You can dead-drift it, skate it a bit to form a V-wake on the water's surface or do a combination of the two. It really is a fun fly to fish.
I'm going to tie this one on a Dai-Riki #310 Straight Eye hook in a size 18, but 16's also work very well. For thread, I'm going to use Danville's Flymaster 6/0 in a light brown.
Start your thread at about the 1/3rd point on the hook shank and snip or break the tag end off. For a little flash, snip a 3 to 4 inch segment of small mylar tinsel free from the spool. This kind is silver on one side and gold on the other. Orient the tinsel so the gold side faces you and secure it, gold side out, to the hook shank. As you can see, the tinsel will fold over when you begin to wrap so the silver side faces out, which is what you want. Take wraps a little ways down into the bend and then take overlapping wraps back to your tying thread. Secure the tinsel with a couple thread wraps and then snip it off close before taking another turn or two of tying thread.
For the yellow underwing, strip a dozen or so fibers from a yellow saddle hackle while doing your best to keep the tips aligned. Tie in the fibers to create an underwing about a hook shank in length.
For the overwing, repeat the process but this time use fibers from a mallard flank feather. I like to make the overwing just a fraction longer than the underwing.
To firmly secure all the fibers, lift the butts up and take a full wrap around the hook shank and then a few more around the fibers. This really helps to keep them from rotating around the hook. With that done, carefully snip the butt ends off close and take a few more wraps of tying thread.
For the hackle, I like a mix of furnace or brown, and grizzly. Without stripping fibers, just align the butt ends and then place them against the near side of the hook and tie them in. I know this is a little weird, as opposed to either stripping or snipping the butt fibers, but on this pattern the technique works. Wrap all the way back to the base of the wings and leave your thread there. Don't wrap it forward toward the eye.
Get hold of both hackles and begin taking adjacent wraps. These wraps will push the thread up the hook shank while the thread keeps the hackle fibers pushed rearward. Just behind the eye, secure the hackle with 2 turns of tying thread, trying not to trap fibers as you go. Pull the remaining hackle feathers rearward and make 2 jam wraps just behind the eye. Then reach in with fine-tipped tying scissors and snip the feathers off close. Take a couple more wraps of tying thread and then complete the fly with a 4 or 5 turn whip finish. You can then snip or cut your tying thread free.
And there you have it, a size 18 Hornberg Dry fly. Don't forget to try skating it every now and again. You'll be amazed at the results.