Pareto Principle
This is not so much a time management method as it is an observation that can help you work on the things that bring you the most significant positive results:
The Pareto principle states that for many outcomes, approximately 80% of the consequences come from 20% of the causes.
When applied to time management and productivity, this means that you first identify which tasks will give you 80% of your results. For example, if you are a writer, sitting in front of your computer and spending time writing will contribute proportionally more to the finished article or book than researching writing apps and tools.
Similarly, in business, being in front of your customer will have a much greater impact on your sales performance than planning a sales strategy or creating lists of potential prospects.
While tasks that contribute 20% of your bottom line have their place, they should not be allowed to become the place where you spend most of your time. Examples of this would be salespeople in staff meetings, teachers writing attendance reports, and business owners performing basic administrative tasks.
The Pareto Principle is essentially what the 2+8 Prioritization Method is based on.