Study your audience's interaction with your site's information space, and design the presentation of the information to accommodate the users' modes of interaction. Make it easy to find stuff. Specifications explain how the requirements are supposed be implemented and completed. These two kinds of instructions are essential to the successful completion of any web site project. If your site needs a specific voice and tone in order to fulfill its relationship with the user correctly, then codify and document the elements of style that comprise this voice.
Interface design is a topic full of dogma and mandates.
Rules abound for the correct way to place navigation elements on the page, where to place branding, how link color should contrast with background color. . . In Navigation design, it's cruel and unusual punishment to offer chaos instead of guidance, self-expression instead of shared communication. That makes the work of an interface designer a serious challenge, since it is much harder to understand others' needs than it is to know your own tastes. There may not always be glory in it, but service is the hallmark of good design. Study your audience's interaction with your site's navigation scheme, and watch how users go about finding stuff on your site.