Beans shrink when the jar is becoming full.
A Tibetan Dharma practitioner called Geshe Ben Gungyal used to practice by observing his mind. Every day he would place a black pebble down each time he had a deluded thought. He would also place a white pebble down each time he had a virtuous thought. At first the black pebbles would outnumber the white pebbles. He eventually reached the state where days would go by with no black pebbles being put down.
This app allows you to follow Geshe Ben Gungyal's example in your daily practice.
