Instead of asking "how do I achieve X?", ask "what would guarantee failure?" and avoid those things. Often reveals blind spots that forward-thinking misses. Charlie Munger's favorite tool.

Models and representations of reality are not reality itself. A wireframe is not the product. A user persona is not the user. Keeping this distinction sharp prevents designing for the abstraction instead of the truth.

Considering not just the immediate consequences of a decision, but the consequences of the consequences. "And then what?" repeated. Essential for design systems where one change ripples everywhere.

Among competing hypotheses, the one with the fewest assumptions should be preferred. In design: the simplest solution that solves the problem is usually the best. Complexity should be earned, not defaulted to.

Systems where outputs circle back as inputs. Positive loops amplify (viral growth, design debt), negative loops stabilize (user testing, iteration). Recognizing which loop you're in changes how you intervene.

Know the boundaries of what you truly understand versus what you think you understand. Operating inside your circle with awareness of its edges leads to better work and better collaboration with those whose circles complement yours.

All systems tend toward disorder over time without deliberate energy input. Codebases decay, design systems drift, team alignment erodes. Maintenance is not a failure of design — it's a law of nature.