The message you want to convey is the most important part of any document. But how you do it also plays a great role. Font faces, sizes, and colors may radically change the way the reader perceives your content.

Sans-serif fonts, like Arial or Verdana, are universally used in electronic publications intended to be read on-screen.

Serif font families are traditionally used in print media, making reading from paper easier. The basic print text is black on white, but modern printing techniques and electronic media have made room for more diverse colors in documents. 

Monospaced fonts, like Courier, are associated with computer terminals and are often used to represent code listings and machine printouts.

Font colors and background colors are used to draw attention to parts of the text. You should use them with caution, though, as similar colors may lead to unreadable results. A properly chosen set, however, will greatly improve text visibility and readability and may be used to aid accessibility.

You may use custom text and background colors to create infoboxes or quotations.

Text size also plays an important role in driving the reader's attention.

Large text is used for important information that really needs to stick out.

Small text can provide some optional details. You can also use it for information you don't want to expose too much.