I will draw from my experiences in medicine and consulting to give you some tookits for thinking

• Inductive reasoning (Observations → Rule) This is about spotting patterns. In medicine, it’s noticing how a combination of symptoms usually points to a certain diagnosis. The key is paying attention to the small signals that repeat over time.

• Deductive reasoning (Rule → Observation) This is applying a general rule to a specific situation. Once you have a principle, you test it. If it doesn’t fit, something’s off. Maybe the rule needs tweaking, or maybe your observation isn’t what you think.

• Abductive reasoning (Brainstorming / generating differentials): This is the “what could be happening here?” stage. You think of multiple possible causes and test which one makes the most sense. 

• MECE (Mutually Exclusive, Collectively Exhaustive): This is a consulting classic. Break problems down so nothing overlaps and nothing gets left out. When you don't have expertise on the topic, you can rely on this to reason from first principles.

• Hypothesis-driven thinking: Start with a guess, then test and adjust. It's useful when you are in a new domain, unsure what you are doing etc. 

• Thesis / Antithesis / Synthesis: Look at opposing ideas and combine them into spectrum. I find it useful to help spot blinds spots, but also to avoid groupthink.

• First Principles Thinking: Step back, start with what you know for sure, then reason from there, don't rely on assumptions.

• 80/20: Focus on the most important driver, don't overcook it. 

• Issue Trees: It's a visual way to breakdown large problems into smaller ones.