Own something valuable and then borrow against that thing. Easiest example would be to own stock worth say a thousand dollars and borrow a hundred dollars from that stock value you get to keep the stock worth nine hundred dollars growing in value while you pay the one hundred dollar "debt" off. If you ever get to where you could not pay it for some reason, you could always take $100 and pay it off immediately. I've heard this referred to as the buy borrow strategy and some people to avoid taxes will use this perpetually and they call it the buy borrow die strategy. Selling an asset often involves extremely heavy extortion from gangs that we call governments, where borrowing from the value of that asset does not incur such an extortion penalty.
Edit: The most important part though is just to make more than you spend from whatever you do.
Tbf, most tax authorities haven't been completely captured by billionaires and they recognise what your just described as a disguised remuneration package.
It works even in the United States. If you sell a stock within a year of owning it, you get charged like 30% extortion. If you sell it after a year, you get charged your normal extortion rate. And if you borrow from it, you get charged zero extortion.
Yeah, that's what I'm saying. Other countries haven't had their tax authorities completely captured by billionaires.
Its funny, wage thieves are happy to charge a levy on other peoples labour, for using their things to make money, but as soon as a country comes along and says "yeah, so, about that whole charging people for using our things to making money thing...." they act like you just asked to fuck thier mum.
And they'll look you dead in eye and claim its a moral issue too, without a hint of shame.