According to James Clear, there are two ways to live longer:
 
#1: Biologically 
Extend the timeline between your birth and your death.
 
#2:
Psychologically 
Fit more lives into whatever time you are given.
 
For #1: you can eat healthily, exercise, sleep well, get outside, develop deep relationships and live with purpose.
 
For #2: you can make each year rich with experiences and live the equivalent of many "lives" in one.
 
And, there is a 3rd way to de-age.