The basis behind using technical analysis is to find trends when looking at the forex charts and be aware of when they first develop so you can ride the trend until it ends. The foreign exchange market is a very strong trending market, lots of ups and downs in short periods of time, and is, therefore, a place where technical analysis can be very effective.
But even considering the great amount of indicators available, there are still many traders every week who still end up buying (being "long") while the currency pair is in a basic downtrend, or selling short when a market is in a uptrend. This is, they end doing things backwards.
If you want to become a profitable forex trader you will need to use as many technical indicators as you want, or create a personalized trading strategy based off a combination of indicators, to recognize the trend. In other words, professional Forex traders try to identify the major trend, the intermediate trend, and the short-term trend and then construct their trades in that direction, based on how long their rules allow them to hold a position.
If the action of the market shows your judgment to be correct, the successful trader 'stays with the market' and endeavors to make the maximum profit on each trade, according to his/her risk-to-reward / equity management rules. If and when the market goes against him/her, the smart trader will take profits and get out. In a narrow market, when prices are not going anywhere to speak of, but move within a narrow range, there is no sense in trying to anticipate when the next BIG movement is going to be - up or down.
In short, if you want to be in good profitable terms with the forex markets you must follow this words of wisdom: “Never argue with the market, or ask it for reasons or explanations”.