..that's why there is stop loss/targets because it will save you to maximize your profits and minimize your loss.
It's a good point to always set a stop loss or target in every trader so that they will know about their loss, if your strategy will not work at once or twice, don't let it will happen next, find another one and try. It seems to sound like trial and error but through this error, you should learn about it and apply it in the next session and avoid not will happening again.
I tend to agree with others there's no accurate trading strategies, all of them are speculating the market try to draw a conclusion which is only predicting the possible outcome but in fact, it's unpredctable and no really knows what will happen next.
All strategies are still subject for trial and error and if they work out, that's the time that we will start developing them. But even how good a strategy is, it won't be perfect and it won't works forever. You should always find another strategy that will suit on you and works on you when you are seeing that your old strategy is not profiting anymore. However, setting a stop loss is more advised every time we trade so that we know when to stop when we are experiencing consistent losses in trading. Minimizing our loss and maximizing our profits instead.