The 80/20 rule, also known as the Pareto principle, states that we need to focus on the few things that get us the most benefit. 
For a lot of events, approximately 80% of the effects come from 20% of the causes. So pick the 20% of your tasks that yield 80% of the results and outsource or simply discontinue the rest.

Living the 80/20 Life

Having the ability to choose is a power. It allows you to make deliberate choices. It allows us to go where we want to go. and most especially, it prevents us to be controlled by what other people want.

The Power of Choice

Choose three Most Important Tasks for each day, and focus completely on gettting them done within a specific time. 
If you add more than three, and you might not get them all done. By limiting yourself to a small number of things, you force yourself to focus only on the essential.

The Most Important Tasks (MITs)

Distinguishes the vital few from the trivial many and eliminate the nonessential.
When you are doing too much at a time, you are constantly switching from one task to another, constantly interrupted, constantly distracted. Do less, clear away distractions, single-task, and get more done.

Less is More

Instead of following a to-do list, make a shorter one called "success list". Why make one?
<ul>
<li>It aims you in a specific direction </li>
<li>It is an organized directive.</li>
</ul>
If your to-do list contains everything, then it’s probably taking you everywhere but where you really want to go.

Success List

To get better results, do less but do it better. Many of us work in an endless stream of tasks, emails, notifications, meetings, multitasking in the process, never pausing and never ending. Pursuing more and more every day. Information overload is killing our brains.

Living the 80/20 Life

Similar ideas to Living the 80/20 Life

Use the 80/20 Rule

80/20: Pareto's principle

Focus On The Few Things Give Most Benefits