http://cherryleewanli.wordpress.com/2008/09/

Scale

Always compose with a scale, whether it’s the traditional scale developed in the sixteenth century that we’re all familiar with, or one you create on your own. A scale is important because it establishes a typographic hierarchy that improves readability and creates harmony and cohesiveness within the text.

Emphasis

Giving emphasis to a word without interrupting the reader is important. Italic is widely considered to be the ideal form of emphasis. Some other common forms of emphasis are: bold, caps, small caps, type size, color, underline or a different typeface. No matter which you choose, try to limit yourself to using only one. Combinations such as caps-bold-italic are disruptive and look clumsy.