The Elk Hair Caddis is the most common caddis imitation in the west and has caught countless trout. The fly floats well in rough water, but will work reasonably well in slower water as well.
Caddis and Sedge patterns are a "must have" in the fly box through the summer months. Caddis can be hatching from May to September depending on your location. Caddis dry flies can be an extremely productive and exciting way to fish as trout love to take these bugs off of the waters surface. Although the fish are extremely willing to eat caddis bugs, sometimes there are thousands of Caddis laying on the water and they may be sitting on calm water allowing the fish to get a really good look at them. When there are a lot of bugs on the water and/or on calm water the flies you fish need to match the bugs on the water because trout can become selective during these conditions. There can be different sizes and colors of caddis hatching at the same time on the same stretch of river so it is a good idea to have different sizes and different colors of different caddis patterns in your fly box. It is also important to carry a varied selection of Caddis Larva in your fly box as they can always be found below the waters surface where fish spend most of their time feeding. You can also add a dropper nymph under your dry fly if you want to cover your basis for those fish that are focused on just dries or just nymphs.
Sold by the dozen. At .74 cents a fly you buy in bulk and save $$$