The tendency for your skis to break into a skid is at its greatest at the end of the turn. At this point, centrifugal force and gravity act together to pull you directly down the fall line. That is why so many turns which start by carving end up in a frustrating skid. There are several techniques which can help prevent this.
Pressuring The Back Of Your Skis
The first technique for beefing up the ends of your turns is to apply more weight to the tails of your skis. It is always the back of the ski which breaks away first if you overload your ski. As you finish your turn, let your pressure move progressively back until you are pushing vertically down through your outside heel. This lets the back of the ski determine the radius of the turn and prevents it from skidding out.
Foot Drive
A second and related technique is a powerful and versatile one called foot drive. It can solve even a very ingrained problem at the end of your turns, and can be used to gain extra purchase on hard, icy surfaces. The trick lies in pushing your outside foot forwards as you complete your turn. This slices your edge into the snow and shifts the pressure onto the tail. The trick lies in then projecting your body forwards sufficiently during the following initiation so that you regain your balance over your skis.
Take your normal high speed cruising turn...
[Photos: ifyouski.com]
...and use foot drive to make your skis stick like glue at the end
of the turn.