A trading strategy is useless if you lack the discipline in following the rules of your strategy. Also, it is very important that you follow risk management along with the trading discipiline.
You need to overcome your emotions and be able to analyze trading as a psychological activity. Discipline can be mastered over time. You need to do study the markets first by observing the fundamentals for the asset involved. Hence, you need patience to control greed and fear.
The next thing is trading plan. Write it down the rules for your entry and exit signals. Hence, discipline becomes the prerequisite for success in trading.