Another no-brainer. The body shape here generally suggests the slimmer silhouette of a large class of mayfly nymphs known as swimmers. The Pheasant Tail was originally designed for fishing spring creeks and is still one of the best patterns for flat, clear, shallow water and tough trout. But that's not the whole story. Fished deep, in tandem with a heavier nymph, this fly will take large trout. In size 18 and smaller, the pattern does double duty as a midge pupa in rivers or lakes.