simple................................

 It's so simple: you spend less than you earn. Invest shrewdly. Avoid toxic people and toxic activities. Try to keep learning all your life. And do a lot of deferred gratification. If you do all those things, you are almost certain to succeed. And if you don't, you'll need a lot of luck. And you don't want to need a lot of luck. You want to go into a game where you're very likely to win without having any unusual luck.

-Charlie Munger, as quoted here