Discipline is a very hard thing to incorporate.
In my view, if i follow a pure trend following method in a very range bound market, i will get ripped to shreds. No matter how stringently i follow the rule, if I dont have confidence in the system i follow, i'll have a hard time keeping my capital intact.
So the very first thing i do is back test my system and then do a manual bar by bar replay of the system and note down the performance. The risk reward ratio of the setup should be atleast 1:2 and strike rate should be atleast 50%. I test it under different phases of the market and only when i feel satisfied with the results, i fix the set of rules. The prime requirement from my system is that it should clearly tell me the trend, the strength of the trend, the stoploss, the entry and the exit point.
Now during trading hours, I know my system's past performance. So having faith on that is not that difficult. The moment i enter a trade, i immediately punch the stoploss order. I never revise the stoploss downwards. And the rest of the day is spent just blindly following the system without thinking about performance. All i know is end of the day, i'll be in profit. If the day ends with a loss, all i care about is that i followed the system like a book and i did not take any liberties. End of the week, I'm confident my system is bound to give me profits.
End of the day, i evaluate my performance only on one parameter: my ability to stick to the rules. End of the week, i compare the performance with a bar by bar replay with that i have achieved and work on areas that need improvement.
Most people i met have never back tested their methods. That makes them skeptical of every trade they take. When in profit, they book early fearing loss of profit. when in loss, they dont exit simply because they are in the hope mode. End of the week, they scrap the system and search for a new system only to get the same result...
Trading is just a procedure. clear set of instructions will ensure the same result over any period of time. Lack of this clear instructions will only result in emotional atyachar by the market...