I really like the "Zen" of the Python programming language. At some point, it became so popular that it even got included in the interpreter as 'import this'.

The "Zen" is made up of principles that guided the language's development. But they're so universal that it seems like they fit for just about everything. With a few tweaks in phrasing, you can apply them to any life process.

The Zen of Python

Beautiful is better than ugly.
Explicit is better than implicit.
Simple is better than complex.
Complex is better than complicated.
Flat is better than nested.
Sparse is better than dense.
Readability counts.
Special cases aren't special enough to break the rules.
Although practicality beats purity.
Errors should never pass silently.
Unless explicitly silenced.
In the face of ambiguity, refuse the temptation to guess.
There should be one-- and preferably only one --obvious way to do it.
Although that way may not be obvious at first unless you're Dutch.
Now is better than never.
Although never is often better than right now.
If the implementation is hard to explain, it's a bad idea.
If the implementation is easy to explain, it may be a good idea.
Namespaces are one honking great idea -- let's do more of those!

And it was written by one of the main contributors to the language – Tim Peters.