My go-to sea-run cutthroat pattern for fresh water is Mike Kinney's reverse spider in various colors (usually hot orange body with wood duck hackle). If they can be found feeding on top, IO use blue-winged olives, little yellow stonefly imitations and, of course, October caddis in the season. For saltwater, Miyawaki's beach popper and various baitfish patterns. I, personally, don't care for heavily-weighted flies like Clousers and don't think they are really necessary.