Daniel Kahneman advocates for recording your decisions in a dedicated decision journal. A good decision is known before the outcome. It involves a mental representation of the facts known at the time as well as applied judgment. Good decisions are valuable but they are more valuable if they are part of a good decision process because a good process allows for feedback about where you can improve. This feedback, in turn, allows you to constantly get better at making decisions.
Giancarlo Angulo's Blog