As a fellow instructor I want to say what was covered in this video was done well. Some good drills but the leap from railroad tracks (with a fast tempo) into high performance medium radius carved turns (with a slower tempo) I don't think is realistic for an intermediate skier who was previously making skidded basic parallel turns. Intermediate skiers are unlikely to know how to balance with more/most of their weight on their outside ski, so some time needs to be spent explaining how that's done in combination with the edging drills that were well explained. Helping skiers that are skidding their turns learn how to blend the tipping/leaning of their bodies with moving their torso (using hip angulation) back towards their outside ski is (in my view) a critical piece of the the puzzle that a student/guest needs to learn BEFORE they can start experiencing some success with carving. I've found that intermediate skiers can advance a lot more quickly IF they understand the WHOLE picture, which also includes explaining the design of the ski and how/why it turns when it's tipped up on an edge. And finally there is turn shape and how the rate at which you turn your feet and legs must take place much more slowly (than most intermediate skiers are accustomed) and in sync with the size and shape of the turn being made. YES, this is A LOT of information, but our brains are much happier when they thoroughly understand how all the pieces of the puzzle fit together. When a few pieces are left out the chance for confusion and misunderstanding increases.
One thing I seriously struggled with until recently, and is clearly demonstrated at 4:26, but not mentioned at all: The inside ski needs to come ahead of the outside ski. If you try to keep the ski tips even, you won’t be able to get the proper lean in order to edge the skis.
When starting to get into carving (after a HUGE break in my skiing career) I found that, rather like some of issues in the other comments here, it was hard to work out how to balance correctly as I started the turn and also how get the ski bending more in the middle of the turn and then stop it from skidding out at the end. I sorted that by leaning toward the tip of the outside ski which made my hips move to the inside, tipping the skis on their edges and starting the turn. More lean bent the ski more and decreased the radius. Then I had to back off the power and have more even fore-aft weight distribution toward the end of the turn to keep the whole ski on the rails and prevent skidding out. Once I had sorted out the balance, power and fore-aft issues it was time to get more into the tipping to make the turn transition more effective. [Kingussie or Grantown Grammar? 🤔]
I'm returning to the snow but can't remember where I was at beyond learning parallel turns. I remember there were a few drills where you'd put all your weight on your downhill leg as you turned to the point you could almost lift the uphill leg off the ground. And there was some talk about edges. Do you think that was a drill progressing wedge to parallel or for further progressing parallel? I can't remember! 😆