Years ago at one of my beginner tying classes, the instructor had us tie the Brassie, one of my favorite flies for fishing the South Platte River in Colorado which is the origin of this fly. The Deckers area of the South Platte can be very demanding and technical. Those fish have probably seen all kinds of flies but the Brassie in the right size will hook them every time.
The Brassie is a fly that can imitate both a midge and caddis larva. Here is how I was taught to tie the Brassie and some additional variations that can be very effective.
Brassie
Hook: your favorite brand, style & size
Thread: black
Body: copper wire
Thorax: muskrat dubbing
Brassie Variations
White Winged Brassie
Hook: your favorite brand, style & size
Thread: black
Body: copper wire
Wing: white zlon or pearl krystal flash
Thorax: muskrat dubbing
Spiral Ribbed Brassie
Hook: your favorite brand, style & size
Thread: black
Body & Ribbing: copper wire
Thorax: muskrat dubbing
Spiral Ribbed Brassie
Hook: your favorite brand, style & size
Thread: black
Body: copper wire
Ribbing: black or other colored wire
Thorax: muskrat dubbing
Brassie (Herl Thorax)
Hook: your favorite brand, style & size
Thread: black
Body: copper wire
Thorax: peacock herl
Brassie (No Thorax)
Hook: your favorite brand, style & size
Thread: black
Body: copper wire
Thorax: none
Head: black thread
Bead Head Brassie
Hook: your favorite brand, style & size
Bead: gold or your favorite color and size
Thread: black
Body: copper wire
Thorax: muskrat dubbing
Red Brassie
Hook: your favorite brand, style & size
Thread: black
Body: red copper wire*
Thorax: muskrat dubbing
*Tying note: use any color wire that is available on the market for tyers
2 Wire Brassie
Hook: your favorite brand, style & size
Thread: black
Body: 2 strands of wire; color optional
Thorax: muskrat dubbing
3 Wire Brassie
Hook: your favorite brand, style & size
Thread: black
Body: 3 strands of wire; color optional
Thorax: muskrat dubbing
Tying Note: The flies above are just a sampling of different ideas for tying the Brassie. Try different combinations of wire, herl dubbing and wing materials. Try tying it as a soft hackle.
References
Excellent history and photos can be found in Tying Small Flies by Ed Engle and in Popular Fly Patterns by Terry Hellekson.
