Head down posture: You can't breath when your head is down. Rolled shoulders, stooped over posture and bent waist will restrict movement.
Note forward shin angle: An ACUTE lower leg angle is paramount to proper form. look at your lower leg angle (shin). In the head on view note the weight shift (transfer) left to right (or lack of). NOSE-KNEE-SKI. Get the hips over the foot.
POOF: Push Off Outside Foot. "Overshift" your weight to the outside of your foot for a more dynamic and longer push/stride.
Big remember: There are ONLY two ways to ski faster; turn it over faster or increase your stride length....I saw nobody over-striding out there.
Don't sweat the small stuff when watching but note that what you do here WILL TRANSFER TO SNOW. As we said last week: Practice makes permanent....not perfect.
See the videos at: http://www.flickr.com/photos/54192844@N02/
Now that you are fully perplexed, discouraged, stiff and hung down remember this; you are doing more right than wrong and this is a brutal workout. If this was easy there would be a lot more folks doing it. It was a solid effort and next week expect a few new ideas and a faster rotation (oh great!). Good work and enjoy the DOMS....you are welcome. What goes up....http://www.youtube.com/watch?v=jfWOzzy381Y&feature=results_video&playnext=1&list=PLF57973E82692C232