In my opinion, the best way is earning crypto interest. I realised this fact some time ago. I tried trading, staking, even mining, but out of all these methods I prefer earning interest.
It's more secure than trading and staking as earning crypto interest works like a traditional banking deposit. You put your assets on a deposit and wait for your interest to grow. Also you can withdraw any time without losing it (for example, CoinRabbit offers free withdrawals without any service fees). And the APY (Annual Percentage Yield) is higher than in regular banks (Celsuis offers 8.8% on stablecoins).