These are presented as a single fly, or with a trailer such as a midge larva. Midge nymph patterns run all colors and sizes. One of my favorites is the simple brassie in sizes 18-22. Baetis emergers are active for several hours prior to their appearance on the river's surface as duns. During this period they are very actively swimming in the river's current and fall easy prey to the trout.
Flashy tinsel is used as a wing case to add brightness to the fly.
This is very useful when the water has a slight stain or cast to it. Most good nymph fishing riggings will catch fish if you pay attention to fishing at the right depths of the water column, and work to get good dead drifts of your imitations to the trout. Adult midges emerge daily in the early season and can provide exceptional dry fly fishing. Trout that are midging are sometimes only noticeable by their smutting rises, so you will have to watch for them. I prefer simple, sparse adult midge patterns in grey, olive, tan, or black.