Prior to addressing layout and look and feel, I like to thoroughly map the page flow of critical tasks. Some page detail can be in these diagrams, but they are not graphical specifications. Their primary job is to define navigation.

When I need to map user actions with reference to specific graphical elements, I like to show those elements and write in the process information in the same frame. There can be a fine line between this and well-annotated wireframes.

I used this image to define the central tab-based navigation pattern for a corporate web application. It was important to keep this simple and clear because it was used to communicate the early direction of the project to engineers, marketers, management, and clients.

A hierarchical model shows the choices and paths a user can take from a starting point. One value of this type of model is that it illustrates the surface of the experience, where the user first starts to do something, and shows how deep into the system they must go to do it.

This illustration shows what a user must do to create, find, and/or edit something; one of the central tasks in this system.