Even if you rent the rest of your ski or snowboarding gear, buy a pair of real ski socks as a treat for your feet. Do not think for a moment that your old gym socks will be good enough for a day of skiing or shredding. The wrong socks will sag, wrinkle, cause blisters and make the best ski boots feel like badly-fitted cement overshoes. If your feet hurt, even a foot of fresh powder on a sunny day with half-price lift tickets can be misery.