[header] How to keep your lips moist [title] Drink more water. [step] One of the best ways to defend against dry, damaged lips is to make sure you're hydrated from the inside out. Aim to get at least 2 liters (about 8 glasses) a day. 
As an added bonus, loading up on water will also make your lips appear more full. [substeps] Carry a water bottle or thermos with you so you'll have something to sip on all day long.