The 90/90 Rule by The Minimalists

The 90/90 Rule is the most effective decluttering test because it cuts through emotional attachment with a single binary question. Ask yourself: have you used this item in the last 90 days, and will you use it in the next 90 days? If the answer is no to both, it must go. This method outperforms #5's typical guesswork by replacing subjective feelings with a strict, time-bound standard. In practice, minimalists report removing 40–60% of their belongings on the first pass, a concrete reduction that proves its efficiency. The rule's simplicity makes it brutal yet liberating, ensuring you keep only what is genuinely useful or meaningful.