by Chris Tyler:
Nut Bar Project, Part 0: Create a rounded cube with inset region using subdivision surfaces
This tutorial shows how to create an inset cube with rounded corners using an ideal method. This method uses a simple polygon mesh ‘cage’ that is subdivided. This approach is better than using other methods because it is easily UV mapped and controlled to scale to different sizes.
This tutorial leads to a package design tutorial, with a containing shape whose construction is based off this modeling approach.