Paid surveys
These involve answering online questionnaires for a few cents or euros. It's a simple way to learn how consumer panels and payments work, but the income remains very limited. You can earn a small gratification, but not a real supplemental income.
Specialized freelancing
Beyond general platforms like Upwork, there are specialized sites (for example, for translators, developers, or graphic designers). Here, your expertise is valued, and you can build a solid reputation. This requires time and consistency, but the income is proportional to your skills and your ability to deliver quality work.
Conservative investments
Rather than jumping straight into forex or staking, some prefer to start with more accessible financial products like ETFs or regular savings plans. The returns are less spectacular, but the risk is also lower. It's a way of putting your friend's logic into practice: investing your energy and money in something that can grow in the long term.