In my opinion, there is no key strategy every trader can adapt to be successful and profitable when they trade Foreign Exchange because every strategy will be used slightly differently with every trader. I suggest going through all the strategies in your demo account, and really exhaust all options your brokerage company has given you access to. You want to make sure you feel confident when using your strategy and make sure you use it in the market and it comes naturally and easily.
All strategies will feel different to every trader because every trader, I believe, truly trades differently. Forex trading is all about eliminating the losing trades and achieving more winning trades. More often than not, traders will rely on trading strategies that haven’t been tested thoroughly or they themselves haven’t practiced enough and setting themselves up for failure. You can spend hours searching all over for the right strategy and have no such luck finding the perfect one.
The only solution is to try out the leading strategies for yourself and see what makes sense to your style of trading, and what sticks. There are many strategies your broker should have made available to you when you’re going through the educational portion of your trading journey, and you should be exhausting all these outlets. The head trader at my brokerage company, Shawn Lucas, in my opinion, uses many different strategies based on what the market is showing him at the time. Currency trading strategies are really a game of trial and error, so it's wise to go through and practice as many strategies as possible so you’re familiar and comfortable using them in case you need to switch it up based on what the market is showing you.
Traders may feel the pressure and stress from having their funds affected by short term moves, and traders will have to fight the urge to close out their trades when it’s losing points. I tend to use positional trading a lot of the time, which just means having your trades open for a longer period of time, so you can catch some large market moves. With a positional trading strategy, you have to dedicate your time to analyzing the market and predicting potential market moves. Shawn Lucas gives the assumption that making a profit and following a set of guidelines is much easier then it is, but being in the Forex industry, you have to be willing to adapt along with the market, and that includes adapting and managing your strategy. You should experiment, change, and improve before you choose the one strategy that suits you best. Trading is very rewarding, and I wish you all the best of luck! Don’t give up on yourself.