Decision quality vs. outcome quality
The most important distinction in decision-making is the difference between decision quality and outcome quality. A good decision can produce a bad outcome (because of luck or unforeseeable events), and a bad decision can produce a good outcome (for the same reasons). If you judge decisions by outcomes alone, you'll learn the wrong lessons. The goal is to build a process that consistently produces good decisions — and then accept that some percentage of good decisions will still produce bad outcomes. Annie Duke's concept of 'resulting' captures this error: evaluating the quality of a decision based on the quality of the outcome.
Know your decision type
Not all decisions deserve the same process. Jeff Bezos distinguishes between Type 1 decisions (irreversible, high-stakes — take your time) and Type 2 decisions (reversible, low-stakes — decide quickly). Most decisions are Type 2, but most organisations treat them as Type 1 — which produces slowness, over-analysis, and decision fatigue. Build the habit of classifying every decision before you decide how much process it needs.
Use mental models as decision filters
Mental models are frameworks for thinking about problems. Inversion asks 'what would guarantee failure?' Second-order thinking asks 'and then what?' The pre-mortem asks 'imagine this has failed — why?' Each model provides a different lens on the same decision, revealing risks and opportunities that a single perspective would miss. Charlie Munger's 'latticework of mental models' is the practice of applying multiple models to every important decision — because no single model captures all of reality.
Counteract your cognitive biases
Every human decision is distorted by cognitive biases: confirmation bias (seeking evidence that supports what you already believe), anchoring (over-weighting the first piece of information you encounter), loss aversion (fearing losses more than you value equivalent gains), and dozens more. You cannot eliminate biases. You can build processes that counteract them: seek disconfirming evidence, consider the base rate, use decision journals to track your reasoning, and create accountability structures that challenge your assumptions.
Build a decision journal
A decision journal is the single most effective tool for improving decision quality over time. Before making an important decision, write down: what you decided, why, what you expect to happen, how confident you are, and what would change your mind. Revisit the journal periodically to compare your predictions with actual outcomes. The journal reveals patterns in your thinking — systematic biases, recurring errors, areas of consistent accuracy — that no amount of introspection can surface.
Separate the decision from the decider
The best decision processes separate the information-gathering phase from the decision-making phase, and separate both from the ego of the decider. Techniques like the pre-mortem (imagine failure before deciding), red teaming (assign someone to argue the opposite position), and the 'disagree and commit' framework (decide, then align) all serve the same purpose: they create space between the decision and the decider's identity, allowing the decision to be evaluated on its merits rather than defended as an extension of someone's ego.