When you can control your speed, you can both push your limits and remain safe on skis. To avoid going too fast, you must control your edges. Edge control allows you to turn, kill your speed and stop. Turning, slowing down and stopping use the same motion but require different distributions of weight with regard to forward and back. Stay over the front of your skis as you turn to set and edge and carve; weight the tails of your skis to scrape and skid and stop.
Bend your knees at least 30 degrees but not more than 90. The faster you go, the more you should bend. Create a perpendicular line -- in relation to the skis -- with your shoulders and knees. Put your hands in front of you. Bend your elbows at the angle of your knees. The faster you ski, the more you bend your knees and elbows. Bring your hands to your chest. Keep your eyes looking down the fall-line, the path a snowball would take if it rolled down the slope.
Set your two uphill edges, the edge below the arch of your downhill foot and the edge below the outside of your uphill foot, by moving your hips off the parallel line between your shoulders and knees that runs perpendicular to your skis. Shift your hips to the uphill side of the slope. At the same time, rotate your knees off the center-line of each ski toward the uphill side of the slope. Though you are rotating your knees hill-side and shifting your hips in the same direction, your shoulders remain directly above your knees, not in front of or behind them.
Rotate your shoulders across the fall-line -- downhill and away from the direction your skis are pointed -- to initiate the rotation of your hips and make a turn; your knees will follow your hips and your knees determine the direction your skis point. Transfer your weight to the downhill edges of your skis to carve a turn -- the turn being the moment you have the opportunity to kill your speed. As you transfer your weight to your downhill edges, lean back in order to move your shoulders behind your knees, breaking the perpendicular line between your shoulders and knees and the skis. Shifting your weight to the tails of your skis initiates a slide, which kills speed.
Recover from the slide by leaning your shoulders forward over your knees in a parallel line that runs perpendicular with your skis. Set your edges by shifting your hips hillside and rotating your knees in the same direction, then initiate a turn in the other direction. Again, rotate your shoulders across the fall-line, your hips and knees -- and therefor your skis -- will follow. Shift your weight to your downhill edges to initiate the turn and lean back to skid and kill your speed. Avoid going too fast on skis by reproducing this motion every time you initiate a turn.