To put my money where my mouth is, in each new article I'll build a hypothetical application that illustrates the guidelines I'm covering. Today's application is called "Paint" and will be based on the photo-illustrative icon I created in my last article. Together we will complete each step, and by the end of the project we should have a well-designed, 95%-100% Aqua-compliant application. I'll leave some room for personal preferences and the fact that Apple changes the OS every few months.

Clicking an application in the dock should always bring forward an active window. If the user clicks on an open app's icon in the Dock, the application is active and all unminimized windows come along with it. I have found a few problems with windows behaving independently of their application.

Adhere to Layout Guidelines. Did you leave 12 pixels between your push buttons? Does the positioning of your pop-up menus make sense, and when do you use a pop-up versus a scrolling list? Are you using the right types of buttons for the proper functions?