All the successful traders on the planet are disciplined traders. They may have distinctive trading techniques however one thing is normal which is they are restrained. Taking in the market and being control is trading is the way to accomplishment here.
@Tremblay yes in trading discipline is very important. Most of the time traders forced themselves to open trade if even their strategy doesn't give proper signal. It doesn't happen if you are disciplined.
Obviously they have been in forex trading for a long time enough to develop a trait - disciplined traders which allows them to do well. But of course, even there are some traders who have been in for long time and can also not be successful as well.
For successful trading, one must use the same strategy for all trades placed. Variations from the strategy can result in losses causing the trader to think that the strategy in ineffective and abandon the strategy altogether