Summarize:

Staying hydrated is a great way to keep your lips moist, smooth, and wrinkle-free. Drinking water also has many other benefits, including clear skin.  If you notice your lips are looking more chapped than usual, drink some water or use Vaseline or another petroleum jelly. There are other ways to stay hydrated as well. Snack on water-rich foods, such as watermelon or cucumber. Sports drinks and coconut water are also great options.  Avoid drinking from bottles, when possible, as this can cause fine wrinkles around your mouth. Bottles with a nozzle-tip should be fine, however. The easiest way to do this would be to cover your mouth with a scarf. If it is too warm for that, or if you simply don't like wearing scarves, consider using some lip balm or petroleum jelly (i.e.: Vaseline) instead. Acidic foods include things like oranges, kiwi, orange juice, and lemonade. Not only can these foods sting your lips, but they can make any current flaking worse. Salty foods may also dry out your lips because of the fine, salty coating they leave on your lips. This does not mean that you have to give these foods up forever; once the flaking stops, you can try slowly reintroducing them into your diet. The more you mess with your lips, the drier and chapped they will become. Biting your lips too often can scrape away the delicate skin, leaving it chapped. Saliva, although moist, actually dries out your lips, especially if you applied lip balm.  If you like to wear flavored lip balm, switch to an unflavored one so you won't be tempted to lick your lips. You can also apply petroleum jelly instead. It doesn't taste good and may help you break the habit of licking your lips. It is very tempting to pick at the dry, flaky skin, but this will only make things worse by slowing down the healing process. Instead, apply a natural, hydrating lip balm instead. Make sure that you use one that is labeled for chapped lips.
Drink 8 glasses (1.9 liters) of water daily. Protect your lips during cold or windy weather. Cut back on acidic and salty foods. Break the habit of biting or licking your lips. Do not pick at your lips if they are chapped.