No video, but a slightly different way of explaining it. Two accessories needed for a good rotary vise are a material holder (usually a spring) that fits around the rotating shaft of the vise behind the jaws and a bobbin holder (a right angled piece of heavy wire with a rubber or plastic tip) that is attached to the vertical shaft of the vise and positioned in front of the jaws of the vise. As you are adding materials to your fly, tie in any that you plan to wrap around the hook shank in the reverse order in which you will wrap them.

So, let's say for example, that you are tying some sort of woolly worm and it will have a body material (like tinsel), a wire rib and hackle. You would first tie in the hackle at the bend of the hook, then draw it back and catch it in the material holder. Next, you'd do the same with the wire rib. Finally, you'd tie in the tinsel. To construct the fly, you'd first advance your thread to the eye of the hook and rest it on the bobbin holder, then wrap the tinsel forward while rotating the shaft. The hackle and wire rib, held in place by the material holder, would rotate along with the shaft (and therefore not tangle). Tie off the tinsel, cut the excess, then wrap the wire rib forward, tying it off and cutting the excess, then do the same with the hackle.

In this example, the material holder held the waiting materials behind the jaw so they would not tangle, while the bobbin holder holds the thread in front of the jaws, with the same result.

Does that help?