Repeat back to the climber what you have been instructed to do when rigging. " Hold tight at first to support the limb being swung with a facecut. When the hinge closes, let it run down away from you (climber). Slow it down before the roof, then stop it. We'll pull it from over the roof with the tagline you put on. I'm ready."
Better than "okay". You know you're working on the same plan.
My $. 02.
Generally, once you land a piece using friction at the ground (lowering device or trunk wraps), pay out a couple feet of slack, and remove the rope from your friction source. Gives slack on the knot, and allows the climber to adjust or remove a block, or the rope from the work area.