1. Limit or avoid exposure to pollutants that can bring damage to your lungs.
2. Prevent infection
Colds and other respiratory problems or infections, can become very serious before you know it. There are some things you can do to protect yourself.
Wash you hands often with soap and water. Use lotion after alcohol based cleaners if you use those, to prevent dry chapped hands.
Avoid crowds during the flu and cold seasons.
Practice good oral hygiene, as germs in the mouth can lead to infections. See dentist every 6 month, and brush teeth at least 2 times a day.
Some people get vaccinated every year against influenza. Talk to your doctor to see if this is good for you. I don't like to personally, but many do.
If you DO get sick, don't spread it around. Cover your coughs and sneezes. Keep a distance from people. Take care of yourself.
3. Get regular healthcare check ups, even if you are healthy or feel good. Lung disease can go undetected until its very serious, and a check up can find problems before you even realize you have one. They will listen to your breathing, and tell you how things are going, and you can ask any needed questions as well.
**The above items are all good to do, I didn't mention quit smoking if you do smoke, as it goes without saying. Your health matters more than you think, its what enables you to enjoy anything in life. :)