Winter often brings with it a number of skin related irritants.  Dry cracked lips is one of those problems.  the air is dry and it's natural to have dry chapped lips in winter.  The best thing so do is try not lick them too often, add a thick moisturizer.  Keep a lip balm with you and whenever you feel your lips getting dry, don't lick, but add the lip balm.  Stay hydrated, avoid the sun.