What Keeps Your Sermon From Fragmenting?

I recently returned from a wonderful week with doctoral students enrolled in Gordon-Conwell Theological Seminary's Doctor of Ministry track, Preaching the Literary Forms of the Bible.  We met on GCTS's Charlotte, NC campus.  One of the things we talked about was keeping our sermons from fragmenting.  Fragmentation happens when I (1) fail to follow the flow of thought created by the Author/author or (2) I choose to replace the existing flow of thought with my own deficient presentation.  We noticed a tendency of not clearly stating the logical connections between moves or thought-blocks in the sermon.  What is clear in the mind of the preacher is unclear to the listener.  While you're developing your sermon double-check all your transitions as you move from major clause to major clause.  Ask if you are carrying the logic forward.  As you know, theology is conveyed more through the logical flow of thought than in the isolated content.