1.Food. You shouldn`t eat junk food,salt,sugar and gluten.
2.Sport. You must go for sport, even if there will be no `result`, just for sparkles in your body and mind.
3.Way of life. No drugs,alcohol and cigarettes.
These are helpful to keep someone healthy and fit and looks like a young but actually you can't stop ageing, it will happen no matter what you are doing.
that`s true but we got some examples, the main one for me is Ronaldo (which is portugese) and in his 34 he is looking better than in his 18 years. Of course there is no way one day we`ll be with face scratched by wrinkles, but somebody is meeting that day in 30 years and another one in 50.