The following suggested 'preacher's decalogue' comes from a seasoned pastor-theologian. Click on the post title to read the author's explication of his 'commandments'; the author, Sinclair Ferguson, is of British Reformed background, so some of the references and background he cites may not be familiar to Lutherans (but there is some Luther in there too). Nevertheless, I think it's a helpful list:
1. Know Your Bible Better
2. Be a Man of Prayer
3. Don’t Lose Sight of Christ
4. Be Deeply Trinitarian
5. Use Your Imagination (i.e. Think Outside Yourself)
6. Speak Much of Sin and Grace
7. Use “the Plain Style”(i.e. direct language)
8. Find Your Own Voice
9. Learn How to Transition (i.e. from the Gospel indicative to the sanctification imperative)
10. Love Your People
Would a Lutheran decalogue for preachers be any different? We'd probably rearrange the order; we'd certainly bump #6 up the list and call it 'Preach Law & Gospel'. We might prefer to call #3 'Preach Christ Crucified' or 'Keep Christ at the Centre' ('don't lose sight of Christ' is a bit weak). And Lutherans would have a different take from most of the Reformed on just how #9 is properly done. But otherwise? And yes, I'm aware that any list called a 'decalogue' can be taken as 'Law'...so, what Gospel do preachers need to cling to?
The article comes from Themelios, which used to be a journal of theology and ministry for British evangelicals but which has now, I see, been taken over by the trans-Atlantic 'Gospel Coalition', led by Don Carson. There are even a couple of Australians involved (one, Mark D. Thompson, is a good Luther scholar). The GC have made Themelios freely available for download, which is nice of them, as it looks to have some decent material. Since this journal comes from outside the orbit of confessional Lutheranism, the usual caution applies: caveat lector.
Oh yes, the pic, in case you're wondering, is of Pulpit Rock, off the coast of Dorset, England.