Read Sri Aurobindo is the short and sweet answer.
But other than that, read good classical writings on diverse subjects including those that seem to oppose your views. Then try reconciling them using your intellect.
Awaken and exercise the discerning faculty and try not to take things on their face value and as they present themselves to your senses and the physical mind.
Reflect upon issues that you feel moved by. Think about them independently and draw your own conclusions. Having done that read what the great thinkers have said about it. Finally read the Mother and Sri Aurobindo on the subject.
Practice quietening of the mind and avoid too much discussion especially animated ones.
Practice austerity of speech. You may read about it in the Mother’s writings on the four austerities.
Don’t misuse the faculty of thought in useless imaginations, fantasies of low and basal things.
Affectionately,
Alok Da