I would say 7 things:
1. cold showers, it increase the immunity and conserves the skin.
2. wake up early (not too early for being tired the whole day) but early enough to be able to have at least 2 hours for yourself.
3. Eat twice a day, preferably morning and evening, believe me our body doesn't need more, and you won’t feel the need anymore when you practice the habit
4. Eat less sugar and moderate meat as possible, especially less of the red meat. Red meat (such as beef, lamb and pork) can form part of a healthy diet. But eating a lot of red and processed meat probably increases your risk of bowel (colorectal) cancer.
Eating too much red meat could be bad for your health. Sizzling steaks and juicy burgers are staples in many people's diets. But research has shown that regularly eating red meat and processed meat can raise the risk of type 2 diabetes, coronary heart disease, stroke and certain cancers, especially colorectal cancer.
5. Avoid some/many fruit juices and soft drinks at way from it!
6. Drink absinth herb tea (without alcohol only the herb!) infuse 10 grams in 500 ml of water, leave for 12 hours and drink it, 3 times per day.
Repeat it the same process for 3 days, It's bitter, buy it will literally kill the craving, for sugar and unhealthy sweets. Do it every six months.
5. Do everything with common sense and moderation, like drinking, spending, sex, etc. socially, not smoking but if you do, never cigarettes.
6. Choose an activity that fit in your life style and that you can do daily or very often with pleasure.
7. Learn always new things.
Our body systems work differently, but these information was gotten from a grandmother, who is 97 years old, happy and healthy.
Hope these helps.