I am currently doing research for a paper about John Henry Newman and the teachings found in his sermons and I came across Newman's 7 rules for writing a sermon. Newman was a great orator (and Oratorian)who, through his writings and sermons, converted thousands of people.
All you priests out there pay attention!
1) A man should be earnest, by which I mean he should write not for the sake of writing, but to bring out his thoughts.
2) He should never aim at being eloquent.
3) He should keep his idea in view, and should write sentences over and over again until he has expressed his meaning accurately, forcibly, and in a few words.
4) He should aim at being understood by his hearers or readers.
5) He should use words which are likely to be understood. Ornament and amplification will come spontaneously in due time, but he should never seek them.
6) He must creep before he can fly, by which I mean that humility which is a great Christian virtue has a place in literary composition.
7) He who is ambitious will never write well, but he who tries to say simply what he feels, what religion demands, what faith teaches, what the Gospel promises, will be eloquent without intending it, and will write better English than if he made a study of English Literature.
Okay, now get to writing those marvelous sermons and start converting souls! And remember, of all forms of Christian instruction, the liturgical homily is to hold pride of place (Dei Verbum 24).