Harbor chop, Sierra cement, mank, moguls: These are all tough conditions to ski in—the uneven snow and terrain can make minced meat of you—so it’s natural to respond in kind, with brute force. But the flailing arms and gyrating hips that come with it betray a skier absorbing too much impact with his upper body and not enough with his legs. Experts’ upper bodies, on the other hand, remain smooth and steady—like a duck’s above the water’s surface—while their legs and feet do the work of absorbing uneven terrain. Only when you move your feet, ankles, knees and hips through their full athletic ranges of motion can you respond to rough terrain with fluidity and grace.