the greatest strategy for losing money

And you need a broker that will treat you honestly and fairly.

Any trading system can be a losing system in the absence of a proper risk/money management.

It's not the system that causes the losses. It is how we use the system that causes the loss. No matter what strategy they use, most people want to trade everyday even if there is no set up according to the strategy.

If you want to lose money, you need not any strategy. Go to the market with the money and invest without any planning.

Ah yes! Some people trade excessively. They enjoy the "high" from winning entirely too much for their own good.