Following the 80-20 rule - What small change in your life yielded the biggest benefits for you?

If you are not familiar with the Pareto principle, here is the link: http://en.wikipedia.org/wiki/Pareto_principle

"The Pareto principle (also known as the 80-20 rule, the law of the vital few, and the principle of factor sparsity) states that, for many events, roughly 80% of the effects come from 20% of the causes." - Wikipedia

For me, going to bed at a set time every night yielded amazing results in energy levels, motivation and weight loss. I can now wake up without alarm clock at 8am every morning. (I go to bed at 11pm) every night... well... almost every night.

What is your story?

This is my first post on Reddit, so be gentle ;)