I’m wonderign what you think are the best ways to ensure a long life with as little effort as possible. I’m thinking things like always wearing a seatbelt. I’m sure that increases your average lifespan by quite a lot compared to the effort involved.
Keep breathing. Don’t stop! 
Sorry, I couldn’t resist!
Zev Steinhardt
The best possible way to increase your life expectancy is to have parents and grandparents who all lived long lives. But this isn’t really something you can do much about.
Here are some other suggestions, just based on experience. They’re all well-known and kinda dull, but you didn’t say if you were after ‘fun’ answers.
- Don’t smoke.
- Avoid so-called dangerous sports and similar thrill-seeking antics which carry a realistic chance of SPD (serious permanent damage).
- Don’t stress yourself out. This either means striving to eliminate stress from your life, or, if that’s tricky, learning to handle it better.
- Keep moderately fit, so that your heart and lungs are working as well as they can. This also helps with (3).
- Cultivate a positive outlook on life. Worry less, enjoy more, lighten up a little.
- Learn a little about nutrition and diet, and make some sensible changes to what you eat and your consumptin of the nasty stuff (e.g. saturated fat) that can build up over time and zap you.
- Have lots of great love and sex in your life. Love is the most life-affirming factor of all. As for sex… well, some say it’s a great form of exercise and does you lots of good in all sorts of other ways, but either it will help you live longer or, if it doesn’t, it will at least put a big, fat smile on your face.
- Don’t be in a horror movie and be the confident one who says “I’ll go check it out while you stay here.”
- Get lots of good sleep. Sleep is very under-rated, but it’s essential for good physical and mental well-being, and it’s the time when your body and mind perform lots of vital routine maintenance functions.
- Don’t burn out. Value your leisure time and make sure you get enough of it. It’s nice to be energectic and productive, but relaxation is important as well.
Eat an apple a day, for 36,500 days, and you’ll live to be 100 years old.
Another good way is to be born female. It makees a difference of about 5 years. Again, not something you can do much about.
According to the CDC, in 2000 the top 10 Leading causes (the things that do the actual death-dealing) were:
Heart disease
Cancer
Stroke
Chronic lower respiratory disease
Unintentional injuries
Diabetes
Pneumonia/influenze
ALzheimer’s
Kidney disease
The top 10 Actual causes (the things that are lifestyle/behavioral in nature and contribute to the Leading killers) were:
Tobacco
Poor diet/physical inactivity
Alcohol
Microbial agents (pneumonia, influenze)
Toxic agents (pollutants, asbestos)
Motor Vehicles
Firearms
Sexual Behavior
Illicit drug use
Be like my great-grandmother (who lived to be 102). Be too damn stubborn to die, even when you get pneumonia at 95. Break your femur just before your 100th birthday and almost but not quite crash in the emergency room, and end up returning to your little itty apartment in the assisted living place where you are the oldest resident some time after your birthday party at the rehab place. Rule over your family with an iron fist.
Yeah, I’m bragging, Grandmother was cool.
Some others, some serious, some less so:
- Have long telomeres (sections of repetitive DNA at the ends of chromosomes that wear down over time and are thought to be partly responsible for aging), if telomeres actually do determine longevity.
- Avoid carcinogenic chemicals and exposure to ultraviolet light.
- If you feel like you just have to have that mutation you’ve always wanted, try to make sure it’s somewhere you don’t really need. Tumor-suppressing genes are a bad choice.
- Protect yourself against free-radical oxidation. Keep your superoxide dismutase fully expressed and functional. (If possible, acquire a genome that expresses lots of SOD, and try to get a highly active isozyme.) Ensure that you have adequate supplies of vitamins C and E, glutathione, and natural antioxidants like the polyphenols and lycopene.
- When you reach a certain age, find a cardiologist and keep your triglycerides and cholesterol under control. Take anticoagulants and blood-pressure drugs if they’re recommended. Current medicine is very effective at delaying cardiac problems.
- Be born as late as possible, and in an affluent, developed country. By 2500 standards, 21st-century medicine will seem like blood-letting.
- Have money, or at least good insurance.
I’m very good at 1, 2, 5 and especially 3 and 10. (;
I didn’t know sleep was so important… I generally sleep a lot, but it doesn’t really follow any rythm for long periods of time. It tends to just get very random. Yes, I’m in college.
Wow, GreyWanderer, is your user name a Jane Yolen reference?
I’m guessing it’s a Tolkien reference.
Moved to IMHO.
-xash
General Questions Moderator
And you guessed right!
GrayWanderer’s already arranged to be Norwegian, which gives him a 1.5 year advantage over Americans.
Hey, wait a second. Didn’t the OP say easy ways to live longer?
Quit smoking, find love of my life so as to be able to shag them, no alcohol or drugs, more sleep, don’t eat bad food, do not stress. Eek! The list stresses me out just to look at it.
keels over
Be a Japanese fisherman. Or a Georgian (The Georgia in Eurasia) farmer.
My grandfather just turned 93. He says his secret is that he has a glass of Scotch every day. It’s kind of a family joke because he has more like a bottle every day, but who’s to argue with a guy born in 1911? Hardly been sick a day in his life, and he won’t go to doctors, anyway, even if he were sick.
I do think for the most part it is genetics and a lot of luck.
Don’t be the red shirt guy.
If someone is chasing you with the intent of committing mayhem upon your person, do NOT run up the stairs. Do NOT run down the stairs into the basement. Run out the front door or the back door or dive out of the window, but DON’T trap yourself. 
Don’t be the lead singer in a rock band.
don’t be the first person on screen in a horror movie.
don’t get into a standoff with the ATF in a compound in texas.