The actionable idea I take from the experiments demonstrating the conjunction fallacy is that when trying to figure out how likely some event is, like a break down of relations between America and Russia or major flooding in California, I should try to come up with ways that event could happen, like Russia invades Poland, or an earthquake causes flooding, and remember that the probability of the event must be greater than the probability of it occurring for the reasons I imagined.

This idea can be extended by applying it recursively to the sub events that could lead to the event of interest, like Russia invades Poland, and given Russia invades Poland, diplomatic relations break down between America and Russia. Also, consider other ways it could happen, like America develops Star Wars missile defense, and generalize the sub events, like Russia invades another country.