Here's a picture of me when I was about 16
I've noticed that they CAN look like they did when I was 16, if I do these things:
1) Drink plenty of water (about 3 liters a day,)
2) Use Vaseline on my lips every night before going to bed,
3) Use a chapstick with SPF sun protectant, daily.
4) Days when I don't have time to reapply lipstick all day, I keep a chapstick or gloss in my pocket and apply it every few hours.
5) I don't lick my lips!
6) Occasionally, I use a lip plumper.
7) I also exfoliate my lips with warm water and a tooth brush.
Smoking doesn't help the look of lips either. I don't smoke.
Here are some videos of my favorite lip products
What do you do to care for your lips?