A Guide to WIN32 Clipping Regions

I have been developing Windows applications since Windows 3.1. I have also spent a large amount of time developing on embedded and mobile devices running OSes such as WinCE, Windows Mobile, Linux, and VxWorks. Still my preference is Win32 programming with the WTL framework.
 
My favorite types of programming take advantage of the graphics subsystems and create very intuitive and enjoyable user interfaces.
 
I have known about template meta-programming for quite some time, and have investigated its uses. Lately I have come to the conclusion that it can be used elegantly in a production solution to create a robust and maintainable solution. This seems to be what I spend the majority of my abstract thinking time on.