Strategy gets you a probabilistic edge. Psychology decides whether you actually capture it. Fear, greed, and impatience override logic at the worst moments.
Pre-trade: visualise both the win and the loss before clicking. If you can't accept the loss, the position is too big.
Post-trade: judge the decision, not the outcome. A losing trade taken correctly is a good trade. A winning trade taken recklessly is still a bad trade.
Build routines — fixed session hours, journaling, breaks after losses. Discipline isn't a feeling, it's a system.