practice what you preach
learn before you teach
travel before you reach
and life will be easy.
Go to any social media site, just open any Whatsapp group, interaction nowadays is about preaching. Every one posing around as an expert, every post, every update, every meme, every conversation some how ending up in - you must, you shouldn't
We are constantly preaching others about do's and don'ts without ever introspecting.
So the wisest thing to do is either preach what you practice or practice what you preach and shun hypocrisy in behaviour and in words.