The 3Ss of effective documents: substance, structure and style.

Substance

The content of the document. This is your message, and it is the reason for writing in the first place.

Structure

There are lots of ways you might organise your thoughts and you need to work out which way is best for the message. Generally, I like structures that put the conclusion/recommendation/request first, and follows up with explanation. But sometimes you might decide a strict chronological structure is best.

Style

This is how you present your message on the page or screen. These are the choices you make about typography, use of headings and titles, use of white (blank) space, formatting of tables and charts, etc will affect the reader’s ability to understand your message.