Lip balm, sunscreen and UV suglasses protect you from elements. YOUR FEET Again, synthetic, wool or a combination of these materials are your best bet. Generally, when cross country skiing you do not need heavy socks. The activity will keep you warm. If you wear two pair of socks be sure that you do not restrict the blood flow in your feet.
Some people like to wear a light synthetic liner under their gloves.
Most outside XC g loves are a combination of synthetics and leather or simulated leather. Reinforcement in the thumb area and palm for poling s the mark of a good glove design.