To avoid injury:
I’d recommend not drinking at all prior to getting behind the controls of a moving vehicle - car, boat, airplane, etc.
Wear a seatbelt when in a moving vehicle
Avoid distractions while operating a moving vehicle - cellphones, eating, makeup, reading of Wall Street Journal…
Drive defensively, not aggressively, and obey the speed limit.
Avoid high-risk sports like sky-diving, scuba, and golf (yes, golf). If you must engage in these activities, get good training, the best equipment you can afford, and avoid thunderstorms (which can kill golfers, among other things).
Install safety devices around the home - rubber mats in showers, grab bars for bathtubs, smoke and carbon monoxide detectors, fire extinguishers, etc.
Figure out an evacuation plan for your home in case of fire, and practice exiting at least once a year
Hire someone else to do dangerous chores like shoveling snow, anything requiring climbing on a ladder, etc.
To avoid disease:
Eat a healthy diet with emphasis on fruit and vegetables. Minimize processed foods
Control your weight
Avoid sick people.
Wash your hands frequently.
Take precautions against insect-borne diseases - if you live in a West Nile area, use mosquito-repellant and avoid being outside at dusk and early evening. If you live in a lyme disease area, take precautions against ticks, and examine yourself regularly for ticks. If you find one, consult a doctor about prophylactic treatment. And so on, and so forth.
If you have a chronic health condition requiring medication, take the medication faithfully and regularly.
If you are fair skinned, stay out of the sun. I don’t mean “use sunscreen”, I mean stay out of the sun, and if you can’t, wear long sleeves, hat, etc.
As you get older, get regular screening tests. The ones for women have been covered, but men need to get their prostates checked on a regular basis
For everyone - screening for colon cancer starting… what age was that again? 45, I think - earlier if it runs in your family
Also for everyone - do a monthly skin check to look for signs of skin cancer, usually a change in a mole or long-term blemish that is assymetricaly, or bleeding (meaning it crusts over, bleeds, crusts over, but never heals), of strange or black color, and is larger in diameter than a pencil eraser. Yes, even dark-skinned people need to do this - you’re not as likely to get skin cancer, but you can still get it.
Get regular checkups - how often you need this varies, but at least once every two years. This can help you catch diseases early, when they are either most treatable or most curable (and not just cancer - something like diabetes you want to catch early, too)
Know your family medical history - this can guide you about what you’re most likely to get.
To avoid death:
Well, the bad news is, you can’t avoid death. But if you follow the above, you can probably put it off as long as possible.