In each given moment you can observe two factors in your experience: first a beingness, and second a mental element, thoughts, emotions, whatever it is.
As soon as you are aware of Being along with thinking a natural shift occurs all by itself. This I call a 'moment of practice'. It is the subtle contrast of the stillness that acts, not a mere intellectual discrimination. If we are consistently following this track it will gain strength and purity. That is all what is needed!