Our lips take a lot of abuse but we often forget to protect them like we do our other skin. Lips have no oil or sweat glands and we are constantly exposing them to things that irritate...like spicy foods, citric acids, hot drinks, etc. Plus, during the summer we go from dry, heated air to cold frigid air and back. We are also our own worst enemy to our lips when we "lick" our lips. Saliva evaporates quickly, so while it may feel good, licking your lips can make them drier than before and the enzymes that help your saliva clean your mouth and digest food are much too harsh for your lips.
First, you should exfoliate your lip area once per week. Don't use a harsh scrub. There are gentle lip scrubs that are made just for this area. Jane Iredale's Sugar & Butter Lip Exfoliator and Plumper is a very good one. It's a dual ended tube...so you get both products in one! If your lips are aging a bit, give Instantly Ageless Sugar Lip Scrub by Jeunesse a try. It also helps diminish fine lines around the mouth.
Next, use a lip balm that has a base of beeswax, petroleum jelly or paraffin. These seal in moisture and won't evaporate as quickly as thinner balms or glosses. Use the balm often, expecially if you are out in the wind and cold. Always apply it at bedtime! If your lips are extremely irritated, aloe vera is great. Don't forget the need for sunscreen even in the winter! Suavecito Lip Balm has a beeswax base and is only $3.00. Another good beeswax based balm, Body Drench Lip Drench comes in six "flavors" ($4.00). If you want a little color, try gloMineral Protecting Lip Treatment SPF 15.