The Sparkle Minnow is a flashy baitfish pattern. The body is wrapped in sparkle chenille that throws light in every direction, and the marabou tail breathes and pulses on the swing. A conehead adds weight and a little jig action on the drop. It reads as a small, flashy minnow, and that is enough to pull a strike when trout are hunting baitfish.
Tie it in sizes 4-8. Silver is the default for clear-to-stained water; gold warms it up for off-color or tannic water; olive is the more natural, toned-down option when the flash feels like too much. The flash is the point of the fly, so reach for it when the water is stained or off-color and a drab streamer would go unseen.
Fish it on a swing or a strip. Cast across and down, let it swing through the current, and give it short, sharp strips to make the marabou jump. It works best in normal-to-high flows and when water temps sit in the 46-65F range, with takers from 42F up to about 70F. Cover water - put it past every likely seam, run, and undercut bank and let the flash do the searching.