The 2nd method is by performing a carry trade, where you can profit by buying a currency with a higher interest rate, and selling a currency with a lower interest rate. An example of this would be the USD/CHF (Swiss franc). If you buy USD/CHF, you are buying the USD, and their interest rates are higher than Swiss interest rates, so if you hold the position overnight, every day you hold the trade you will make money, and the money will be deposited in your brokerage account.
The problem is that this is where traders are most likely to succumb to overconfidence bias. It's not uncommon for traders to complete a winning streak and then believe that they can't get anything wrong in the future. To believe this is of course unwise, and is only going to end in failure. Make sure you always analyse your trading sessions and look at your wins and losses in detail.