1. A man should be in 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 to be eloquent.
3. He should keep his idea in view, and should write sentences over and over again till he has expressed his meaning accurately, forcibly, and in 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 and thinks, 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.
This is originally called 7 Rules for Writing Sermons