Cast the Soft Hackle Olive nymph up the river, let it drift and sink, then let it swing downstream, which lifts the fly upwards in the water. If a fish doesn't grab the fly on the dead drift, they will often take it as a rising caddis. The peacock herl in this nymph, when wet, produces a color of nymph that trout can't resist. The olive soft hackle is also effective in lakes as a damsel nymph imitation.