The 10-10-10 Rule

Before any unplanned purchase, ask yourself three questions: How will I feel about this in 10 minutes? In 10 hours? In 10 days? The 10-minute answer is almost always positive — that's the dopamine talking. The 10-hour answer introduces doubt. The 10-day answer usually reveals the truth: you won't care about it at all.

This rule works because it forces your prefrontal cortex back into the decision. You're literally engaging the rational part of your brain that emotional spending shuts down. Try it for one week on any purchase over $20. Most people report cutting impulse spending by a third just with this one tool.