Below we discuss how beginners can make mistakes as there instructors go over techniques. Probably the biggest mistake I've seen on the hill, is the new skier not taking any lesson at all. Often I see on the hill a bunch of guys who are only so-so skiers bring out someone who's never skied at all and they plan on teaching this beginner in just a few runs. This will usually result with a visit to the ski patrol shack.
Video Clip from "The way to better skiing"
This video clip covers two major mistakes skiers make when learning how to ski.
First: leaning back not in the dynamic position not using good posture - Stand centered over your feet with slight bent joints allows you to adjust to position.
Second: Turning with your whole body which does not allow you to set your skis edges so you're not in control.
Weight shifted back
Skiing with your weight shifted back, some instructors will call it "Sitting in the back seat " is a no-no. When your weight is shifted back it can increase your chances falling. You'll go down backwards right on your bottom.
As stated in our Stance and Position section The dynamic stance and posture for alpine skiing is a balanced stance: Stand centered over your feet with slight bent joints allows you to adjust to position. Put your weight forward so you feel pressure on the tongues of your boots, and keep your arms forward. Keep your feet apart about hip width. Hold your hands (and your poles) comfortably in front of your body, as if you're holding a cafiteria tray.
Looking down at your skis
If your looking down at your skis you're not watching wear your going, that's dangerous on skis, you could run into anything. Looking down at your skis can also lead to skis crossing. Besides running into other skiers and crossing your skis, looking down at your skis will put your stance out of the dynamic position, causing stress that makes the shoulders and back rigid, limiting the dynamics of movements necessary even for initial-level turns.
Skiing with your weight shifted back, some instructors will call it "Sitting in the back seat " is a no-no. When your weight is shifted back it can increase your chances falling. You'll go down backwards right on your bottom. 
If your looking down at your skis you're not watching wear your going, that's dangerous on skis, you could run into anything. Looking down at your skis can also lead to skis crossing. Besides running into other skiers and crossing your skis, looking down at your skis will put your stance out of the dynamic position, causing stress that makes the shoulders and back rigid, limiting the dynamics of movements necessary even for initial-level turns.
