Ok this is going to be a bit controversial because a lot of beauty bloggers give tips on exfoliating the lips, some skincare brands sell lip scrubs but I'm going to tell you why you shouldn't exfoliate your lips.
Your lips aren't like normal skin, it doesn't have the top layer (stratum corneum) and doesn't produce any natural oils, your lips are infact a mucus membrane, the same as the delicate skin in your nostrils that gets inflamed and flaky when you have a cold. So if your lips are dry and flaky they need moisture, not scrubbing that's going to irritate them further. If you suffer with dry lips then invest in a good lip balm and avoid anything that's petroleum based, these really don't nourish the lips, for the lips I tend to promote natural beauty and Naturally Thinking have a nice selection.
I had a friend who's lips were so dry his bottom lip was split in the middle and had been for a while, I healed this with lansinoh nipple cream which is amazing stuff for dry, cracked skin, it's a thick, waxy texture and heals cracked skin within a day or two.
With the lack of humidity in the air during winter, this is the time you'll particularly notice your lips drying out so make sure you have a good lip balm ready, apply morning and night and throughout the day when needed. And when we do get sun, remember your lips are at even more risk of getting sunburn so make sure you protect them with a lipbalm that contains an SPF.
Also the tip you may have heard "don't use too much lip balm because then your skin won't produce it's own oil" is not true, it's never produced it's own oil in the first place to slather away!
I know it's tempting to want to scrub lips when the skin is all dry and flaky but it really is going to affect the look of your lips long term. If your lips are nourished they're going to look a lot plumper and healthier and your lipstick is just going to sit a lot nicer, it will only take a few days of regularly applying your lipbalm to get your lips in great condition.
There is also a debate on whether being dehydrated can affect the lips, some say no but I notice a big difference in my lips if I haven't drunk enough liquid throughout the day.
Do you have a favourite lipbalm? If so please let me know in the comments section, I'm always looking for a new one to try.