Traditional gives you more control on groomers and ice, while reverse (upturned tips and tails) floats better in powder.
The amount of "rise" refers to how the tip is curved upward: shorter or low rise for sharper turns on hardpack, long or high rise for powder skiing.
Long skis increase stability in all conditions, and the added surface area keeps you on top of the soft stuff, but short skis are easier to handle and quicker to turn.
The depth the ski is cut from the nose to the waist, which determines its turning radius. Deep sidecut equals quick turns on the corduroy; shallow sidecut is for wide arcs on open terrain.
Narrow (<75mm) allows for rapid edge-to-edge transfergreat for mogulsand carving precision, but you'll sink in fresh snow. Wide (95mm) means you'll float but also work to bring 'em around.
Most shops use wood over foam to increase durability. Heavy woods, like ash and maple, make strong, stiff, and stable skis. Softer woods, like an ash-fir blend, are just as durable but make for a slightly lighter and snappier ski.
Determined by the thickness of the core and the stiffness of the structural layers. Racers want firm, but if you like bumps or tight chutes and powder, go soft.
Wagner Custom, Telluride, Colorado (wagnerskis.com) ScottyBob's, Silverton, Colorado (scottybob.com) Igneous Skis, Jackson, Wyoming (igneousskis.com) Folsom Skis, Boulder, Colorado (folsomskis.com)