In this post, I will try to collate different guidelines and pointers to readings that can help in building/fixing High DPI (HDPI) issues in WinForms
2. Creating a DPI aware application (MSDN documentation)
3. This post on SO has a documentation of some of the design guidelines – How to write WinForms code that auto-scales to system font and dpi settings? and this Creating a DPI-Aware Application
Most of the above points were helpful to me and should cover the most important things to keep in mind while working on HDPI. If you are starting fresh, you have various option like using WPF and building new Modern style UI on Windows 8 machines for which the framework handles the major things for you.