Once you have made object, metaphor, and representation decisions, and have storyboard your scenarios, you are ready to create a high level design for the interface.

• Select/Adapt a Style: an interface standard style should be selected or developed to provide a consistent look and feel for the user interface.
• Identify Main Windows and Related User Actions: identify the main interface windows that will represent the main objects users want to see and act on in the interface in order to achieve their task goals.
• Identify Home Bases and Launching Pads: home base is a screen or window users return to repeatedly while performing a task. It is not necessarily the first screen users encounter. Launching pad is a first screen that is used as a jumping-off point for a large application with several smaller applications within it.
• Identify How Users Access Main Windows: you need to decide on how flexible your interface is for different users and tasks.
• Assign User Actions for Main Windows: make a list of all actions that are in your main windows and home bases.

• Create Design Mockups: your goal in creating the design mockups is to document all the decisions, show how they fit in the actual screens, and prepare a paper prototype that can be shown to others.
• Review and Revise the High-Level Design: test the interface high-level design against your use case scenarios. Evaluate how well the interface organization seems to support how users need to work. Revise the design and associated mockups as needed.