I have a stupid response and an intelligent one.

I'll give you the stupid one first just for fun:

Euro Millions or any other games of chance. Even making online bets, for example. There is no intelligent way to do this quickly.

The intelligent response:

It all depends on where you are in the life cycle and wealth cycle, and the definition of "quickly" is also a factor. Your current education and job are important considerations.

This leads me to my answer: the best way is a well-targeted training program tailored to your specific circumstances. No matter what we do in life, there is always something more we can do. On average, a training program costs around 1000 euros, excluding traditional university education. By investing in the right training and profession, most people will see an increase in their salary. I can't promise you x10, but if you earn minimum wage and a training program helps you earn an extra 300-400 euros per month, that's already 3600-4800 euros per year.

Good luck!