What are some quick tricks or rules-of-thumb you use to help plan/organize/live your life?
I was thinking about planning a project today and was reminded of Parkinson's law: Work expands so as to fill the time available for its completion.
I gave myself less time than I thought I needed for the project and was able to complete it on target.
Which got me wondering...what are some other good rules of thumb, laws, adages, etc. that you use to help you make good decisions on the fly?
Another example that comes to mind:
-the Pareto Principle, aka the 80/20 rule: 80% of the value you create comes from 20% of your work, 80% of your sales come from 20% of your clients, etc.
A reminder to focus on the most important things.
Looking for practical, useful things, not like Murphy's Law,
for instance :)