online banking :-) +bitcoin.
It's not that hard, just make more than you spend. Invest in stocks, crypto, real estate, ETFs, index funds.
Don't forget to join angelist if you are an accredited investor.
Many people find that their spending increases with earnings, and that even if they're earning above average they don't have any savings or pension sorted out.
Most people say it the other way: "spend less than you earn."
But one gives an emphasis on earning more income (more income === more money to save), the other simply limits how much you can spend.
I found that by focusing on earning more, I had to worry less and less about spending less.