I call this fly the forget-me-knot midge. By changing colors and thorax materials you can make it resemble a variety of standard midge patterns. I believe it's the translucent, segmented abdomen that really makes this fly work well.
Although using other kinds of monofilament is fine, 15 pound Amnesia works exceptionally well and is available in 4 different colors. Here we're going to use the 15 pound in red to tie a fly similar to a blood midge.
Start by cutting a 14 inch length of the mono. You can use less, but 14 inches is a good place to start. It's critical to lubricate the line first. Saliva works but pulling the mono a couple of times over a bar of soap definitely works better.
Start by making a simple overhand knot in the line. Keep on going around the loop until you've made 10 turns, you can experiment with this number but again, 10's a good place to start. Gently pull the tag ends of the mono apart like so. Keep pulling to tighten the knot but don't seat it all the way. I like to use small needle-nosed pliers to really get hold of the line on either side of the knot. A medium fast, steady pull will seat the knot correctly and give you a nice barrel shape.
With that done, snip one of the tag ends off right at the knot. Using just the tips of needle-nosed pliers, get a hold of the mono at the other end of the knot and snip it off to leave 1/4 of an inch tag. Take a lighter and melt the mono all the way back to the pliers. It should form a nice, neat little ball. Set this aside in a safe place as they're easily lost on your tying bench.
For a hook, we're going to use a Dai-Riki #125 in a size 22. You can go larger, probably up to an 18 if you'd like. With the hook in your vise, start your thread just behind the eye, here we're using black 70 Denier Ultra thread. Once it's started, snip off the tag.
Get hold of your mono midge body and secure it to the top of the hook shank with a few tight wraps. Add a wrap or two just around the hook shank to prevent spinning.
For the thorax, we're going to use black Super Fine dubbing, but the choice is yours. Make a small dubbing noodle on your tying thread and begin taking wraps to build up a plump little thorax on the fly. Bring the thread around to just behind the eye and do a 3 or 4 turn whip finish. You can then snip or cut your tying thread free.
And there you have it, a Forget-Me-Knot midge. The Amnesia fluorescent green, the red and even their black look great. If you want something in brown, give 12 pound Maxima chameleon a try.