Don't do anything in practice that you wouldn't do in the game.
You might reduce Lombardi's coaching philosophy to a single sentence: In any game, you do the things you do best and you do them over and over and over.
You can achieve only that which you will do.
Nobody whoever gave their best ever regretted it.
Nobody who has ever given his best has regretted it.
Many people flounder about in life because they do not have a purpose, an objective toward which to work.