I have, for the last two years, made an adventure into the world of big flies. I'm not talking size 4 or size 2 streamers on single hooks, I'm talking articulated and single hooked bugs from 3 to 6 inches long. Flies that size make most trout fisherman cringe. Aren't those for pike or stripers? No. For some perspective, most of my pike and musky flies could eat an average wild brooky for desert. Throwing huge offerings gives a fish a choice: run and hide or take a whack at it. I find when using big streamers that a fish will almost never come back for the same fly if it refuses it on the first cast.
I could delve into patterns, but that is not going to go far into it mostly because I don't think I need to. I'll just say this: The Farmy and Housy ARE NOT the White River. Throwing a 7 inch + deceiver will not work very well on our fish. I find that the happy medium is between 3 and 4 1/2 inches, though if you work for a while some big fish will go for a fly up to 6.
I have used a modified technique similar to Kelly Galloup's to fish our waters. I use a floating line in the summer with a four foot 15 lb leader down to 1x or 2x tippet, no longer than a foot. I DO NOT SWING BIG STREAMERS. How often do you think a big trout sees a salmon parr come cruising through the run and stick its tail right in its face? My technique is based on making my fly act like an escaping prey item. I cast across stream, toward a structured bank, and do a fast jerk strip retrieve, letting the line belly and sag slightly in the current. Rather than negatively effect the action, this gives better contact to the fly and each manipulation I do has a greater effect. I often fish straight upstream, Working it towards me with a quick strip that doesn't effect the fly but picks up slack. I raise and drop the rod tip to animate the bug. Heavily weighted flies are preferred for working upstream, lighter bugs, perhaps with dear hair heads for the cross current fishing. Shallow water is key here, 5 feet or less in depth.