On steep and icy terrain, skiers checked speed with a determined setting of the edges. As the master instructors from Austria used to say, "Hit your edges: Zock!" (1). Back then, you kept the skis quite flat on the snow (2-3), so you could steer the skis past the fall line quickly to keep speed in check. Then you'd start to edge again (4). You had to do it suddenly and forcefully, blasting snow with the edges. The bigger the spray, the more precise your control (5).
Smooth Speed Control
Fortunately, skiers no longer have to chop with their edges to slow down. You may need to get the edge deep into the snow, but you do it with a subtler slicing action (A). You should spend as little time as possible on a flat ski, because you want to give it little chance to skid. Change edges quickly (B), but don't romp on the edge. Let the edge set up a new carve even before it reaches the fall line (C). Speed is still controlled with edging, but the secret to speed control in modern skiing is making curves so round they take you back uphill. The important point here is that a slow short turn still has a round shape (D). To work as designed, the ski still needs to travel forward, even if it is skidding (E).