Thought One: the work of the Holy Spirit enables effective preaching ... working in me the preacher ... inspiring the words I will say ... illuminating the text of Scripture in the congregation ... convicting the congregation of the truth of God's Word proclaimed through me.
Thought Two: most weeks I get so far with my sermon draft(s) and hit a kind of wall. This is not very good, I conclude. It needs improvement. Happened this week. What happened in the final revision? (1) I reread the text of Scripture (2) I let the text drive the content of my sermon more than in the drafts to date.
Summary: Word and Spirit; Spirit and Word ... ask the Holy Spirit to help, let the text speak through the sermon!