http://www.harbskisystems.com/hhsite/up-down.htm
In case the text on the image is hard to read this is the same text.
Living on the wrong edges
To learn to carve with a ?High C? engagement, the edges have to be changed before the skis change direction. If you pick out a spot on the side of the slope at the end of the turn, use that point to aim your ski tips at, when you have your spot, don?t change the direction of the skis during the edge change, keep the tips pointing at your spot. This means release the old edges, go through flat, get on the new edges, do not change direction.
Skiers learn that skiing is about turning, but it isn?t, it?s about changing edges and letting the ski?s side cut take you around the turn. Remember the shaped ski should do the work. If you are changing direction of the skis before you engage, you are missing part of the turn arc. Engaging does not mean skidding to an edge at least not in PMTS. Worst; you are missing the real fun of skiing. Speed with control on any condition. If you miss part of a turn arc by skidding into the top of the turn, you have to make up for it at the end of the turn, which means a hard edge set or an up movement. Remember direction change before edge change and skidding to an edge angle are similar.