Become a critic to find the truth.

Watch out for small entities when you hear about statistics.
This includes businesses, households, cities, etc.

Treat people the way you want them to behave.

Become your own toughest critic.
Treat your own internal observations with the same degree of skepticism as you would claims made by a stranger.

Question unsolicited advice.
By doing this, you partially shield yourself from manipulation.

Avoid ad-contained sources.
Books are still ad-free.

Try to remember the source of every argument you encounter.