The absolute best way to do that is by buying stocks. To be more specific I would say by buying big companies stocks as their value in the long term will always increase. You can get some ups and downs but looking at the charts even without scrutiny, you will see that almost everything is going up. Cryptos could be also an option, it is really easy to make more money with this, but you can lose everything as well. And of course, if you have enough money (not my case 🤣) you can buy property, that always increases in price.