Self-control may be developed in precisely the same manner as we tone up a weak muscle,—by little exercises day by day. Let us each day do, as mere exercises of discipline in moral gymnastics, a few acts that are disagreeable to us, the doing of which will help us in instant action in our hour of need. The exercises may be very simple—dropping for a time an intensely interesting book at the most thrilling page of the story; jumping out of bed at the first moment of waking; walking home when one is perfectly able to do so, but when the temptation is to take a car; talking to some disagreeable person and trying to make the conversation pleasant. These daily exercises in moral discipline will have a wondrous tonic effect on man’s whole moral nature. – William George Jordan, Self control, its Kingship and Majesty

Found here – Manvotional: The Kingship of Self-Control