Charlie Munger has a two step filter through which he makes his every decision making problem to pass through.
Essentially he divides the realm of decision making in to two: Real and Subconscious.
1. Understand the forces at play : For every decision to make there are certain factors which govern the choices (rational), it is important to understand these real factors/interests, motivations and probabilities working behind those choices. That is the only way to make a rational choice, to understand the ‘what’ and ‘why’ of forces playing underneath them.
2. Not getting strayed by the subconscious : Once the ‘real’ factors have been assessed and a decision is being arrived, it is highly likely that decision would be morphed by the subconscious minds playing the psychological tricks.
Hubris, Bias and Prejudices are among them.