Target specific lies by allowing the fly to drift into a position so the swing carries it into a feeding lane slightly upstream of a log or boulder. Drop the rod tip sharply, and the fly could fall right into a fish's mouth.
Guide tube jigs into cover. As the lure swings into the current, alternately raise and lower the rod tip to position the lure upstream or down, or to adjust its speed by pulling it into slower or faster currents. For downstream adjustments, open the bail briefly and let the river pull line for a new swing trajectory.