Two tufts of treated McFly Foam about 1 ft apart. I first heard John Wilson describe this technique, and I've found it very effective.
Usually, the lead indicator will shift slightly upstream on a subtle take...SET! you'll catch the strike seconds before the indicator sinks.
This really helps in swift choppy water, where the fish will take then spit the fly before you know what hit it. Especially on rivers like the Watauga.
TW