Heading styles and lists help break up the document into managable chunks of information. You should always be consistant when using the heading styles and be diligent in using the list styles for lists of information. But what about calling the reader's attention to a specific sentence or paragraph without creating a new section?

Certain graphics can be designed so users will know what to expect when one is presented. Consider these uses:

Information Paragraph

This is an paragraph with important information. Please read it completely as it is very important. Lorem ipsum auctor pharetra odio habitant morbi sapien ullamcorper aliquam dapibus congue, euismod ac iaculis ipsum ut varius iaculis pulvinar elit suscipit eleifend massa egestas aliquet et neque sollicitudin suscipit senectus purus in. Ad lacinia fusce sociosqu metus leo praesent dapibus incepto.

Small Alert Block

Create a single color square in any graphics program. Resize it using the Image Properties dialog box as necessary. This block is 12 px wide and 9 px in height.

The above example should always be used in the same circumstances so that the users know what to expect. You could make several blocks in different colors as well.

Icons Used As Contextual Symbols

This gear icon could be used to indicate important processes that should be followed.

For more icon ideas, take a look at Font Awesome. It is a pictographic font with close to 500 commonly used icons you can use to make icon graphics for your site. Complete set of icons can be viewed on a comprehensive cheatsheet.