[no subject]

Chapter title
 Heading 1 (one- to six-page topic)
  Heading 2 (subdivision of heading 1)
   Heading 3 (subdivision of heading 2, seldom used)

In my experience, no matter what typography you use, you won't be able to
make more levels visually distinguishable (unless you do really grotesque
stuff).

I think this is because the poor reader shouldn't have to deal with more
than two or three levels of heading. We can't really see it. We can't easily
conceptualize it. We get lost and confused if more are forced on us.

Further, I run the chapter titles and heading 1 (topic titles) across the
full width of the column, and force a page break for each new topic. Other
headings are aligned with the text column.

Maybe a greater service you could perform would be to flatten your material
down to two or three levels and simplify the heading typography. Study your
application manuals. Try it out. You might like it.

As to typography...

All headings are set in a sans-serif, bold font, and are left justified
unless otherwise specified.

Heading 3 - same (or equivalent for face) size as body text, indents same as
body text, same space above as body para.

Heading 2 - two points larger than Heading 3, indents same as body text,
space above equivalent to two lines of body text.

Heading 1 - two points larger than Heading 2, no indents (i.e. same width as
header and footer), no space above but page break before, thick 25% black
rule above.

Chapter title - two points larger than Heading 1, no indents, no space
above, 36 or 72 points below, thick black rule below, chapter number is in a
smaller font and left justified, chapter title is right justified.