In the words of Pope Francis:
Fast from hurting words and say kind words.
Fast from sadness and be filled with gratitude.
Fast from anger and be filled with patience.
Fast from pessimism and be filled with hope.
Fast from worries and have trust in God.
Fast from complaints, contemplate simplicity.
Fast from pressures and be prayerful.
Fast from bitterness, fill your hearts with joy.
Fast from selfishness and be compassionate.
Fast from grudges and be reconciled.
Fast from words; be silent and listen.