St. Vincent Ferrer on Preaching

"In sermons and talks, use simple language and a homely conversational style to explain each particular point. As far as you can, give plenty of examples; then, whoever has committed that particular sin will have his conscience pricked, as though you were preaching to him alone. But it must be done in such a way that your words do not appear to come from a soul full of pride or scorn. Speak rather out of the depths of love and fatherly care, like a father suffering for his sinful children, as if they were gravely ill, or trapped in a deep pit, whom he is trying to draw out and set free, and look after like a mother. You must be like one who delights in their progress, and in the glory in heaven that they are hoping for. 

"Such a style usually has a good effect on a congregation. For, to speak of virtues and vices in general terms evokes little response from listeners. 

"Similarly in confession, whether you are gently comforting the timid, or more sternly putting the fear of God into the hardened sinner, you must always show the deepest love, so that the sinner always feels that your words come out of pure love. In this way, your words of sweetness and love will have a more penetrating effect. 

"But in your desire to be of use to the souls of your neighbors, you must first of all have recourse to God with your whole heart, and simply make this request of him. Ask him in his goodness to pour into you that love in which is the sum of all virtues, through which you may be able to achieve what you desire."

St. Vincent Ferrer, Treatise on the Spiritual Life; http://www.vatican.va/spirit/documents/spirit_20010405_vincenzo-ferrer_en.html