I'm going to put forth an alternative perspective to all this. Can any of you get very large edge angles going slow on a green run with a wide arc? I can't. Maybe that just shows my focus is on moguls, or it's because the amount of angle that you can achieve carving a perfect arc is related to centrifugal force which depends on angular velocity. So, at slow speeds there is a physical limit to how much lean you can hold without falling over. One way to get the skis to higher edge angles is if the center of mass isn't leaned over as much as the skis. You can do this by angulation. There's only so much angulation the body can do, but if you rotate your upper body to give you some forward bend at the hips, then you can create more angulation then just by bending to the side.
So, this may be a perfect example where the instructor's advice will fail to give the desired results, and NCski will question their skills. When NCski tries to implement all the suggestions in this thread, he won't be able to get the extreme edge angles going slow on a green run. He can try and try and try, but will keep falling over. Perhaps this is why he wanted to see instructor video on a gentle green slope. Probably none of you can achieve the same edge angles at that speed. So, the problem is who cares about high edge angles on a green slope? The best advice for this skier may be to stop working on high edge angles on green slopes. If green slope edge angles are the ultimate goal, then he is perhaps the superior skier to all of us, and we could all learn quite a bit by following his example. If I'm wrong about this then let's get a ski off. Let's get the slope pitch, ski turning radius, and velocity for NCski, and see if anyone can post a video on the same terrain with as much edge angle.