There are different ways of widening our consciousness, which can be categorized as physical, psychological, spiritual.
The physical ways are concentrating upon something that is vast and thereby identifying with it. One can for example concentrate on the image of a sea or the sky or galaxy. all this leads to a natural widening of consciousness. One can even imagine floating upon an ocean or widening until one feels that the stars and galaxies are within oneself.
The psychological methods are to learn and practice equanimity, to try and see the other person’s point of view, to try to see the truth behind appearances, to try to expand the heart and practice generosity, forgiveness and other noble emotions. It also helps to read books that carry within them a vast outlook such as the works of Sri Aurobindo and the Mother. These writings automatically make us vast.
The spiritual way is to think about the endlessness of Time and the boundlessness of Space and then see how small this moment is over which one is making so much fuss. The other way is to ascend to higher states of consciousness through aspiration for the Divine, for His Truth and Peace and Beauty and Light. The higher states are necessarily vast and by ascending to them we too grow vast in our consciousness.
The perfect way however is to identify with the Divine.