Me too. High idle to get the rope tightened and tube pointed in the right direction (you also have the rider's attention at this point), then full throttle to stretch the rope and pop the tube onto the top. Accelerate for just a second, then adjust throttle to your intended speed. You'll do all that without a second thought after a while.
What you don't want to do is yank on a tube, especially if someone that's a little hesitant is on it. There's a good chance you'll yank the tube right out from under them!