Updated: Jan 22
Give away your money.
If you keep it in a bank, your government will print more and devalue it. If you do a fixed deposit or purchase bonds, the inflation-adjusted returns you get are very low. Your country probably imposes a tax on these assets. You can actively trade stocks for higher returns, but trading actively becomes a second job. You still end up paying capital gain taxes. Mutual funds don't demand attention, but the moderate returns are still taxed. There are no ways to protect your earnings without a considerable amount of financial sorcery, which drains away the most precious asset -- time.
The quickest and cheapest way to deal with extra income is to give it away. While you spend countless hours trying to protect your earnings from your governments, time is passing away. Since time is infinitely more precious than money, you can only lose in this transaction. The best you can do is minimize losing time by eliminating meaningless and unnecessary things. It is not an accomplishment to own the world at 70.
Since the system will eventually take your money via taxation, licenses, etc or make it useless by devaluing it, the best you can do is not let them have it either. Give it to the poor. At least, this way we can keep capital out of the reach of the ruling class. If we don't do this, they will only get bigger and stronger.
Giving away the extra strengthens local economies as more people become productive and creative members of society. Someone you gave money to might become a technician and one day repair your phone. He might employ more people and further reduce poverty, in turn, crimes. Having strong local communities is also the best defense against tyranny. Therefore, we do gain massively from giving. The returns are just not quantifiable and immediately observable. But it is always better than letting governments and corporations have your money because they may end up using it against you.
Paper money was invented probably for the very purpose of stealing your wealth. The system and its rules are stacked against you. You will never win a game where the rules are arbitrarily decided and can change whenever the other party wants. The best defence is to not play. Once your glass is full, give away the extra.
By the way, you don't have to make more money than you need. You are only throwing away your life by doing that. Remember the clock is ticking as you engage in meaningless pursuits.