Heirarchy of building blocks: Chapters, sections, subsections, paragraphs, sentences.
Begin each block with an overview:
Report overview: first chapter
Chapter overview: first section.
Section overview: first pargraph
Paragraph overview: first sentence
End each block with a summary
Last chapter: Summary and Conclusions
Last section of each chapter: What did the chapter accomplish? What is important for the rest of the chapters.
Exceptions to rule Overview/summary not necessary if block is too small, or is exceedingly well written. ``self-documenting code''