One of the pains of using WiX is that every component you create has to have its own unique GUID.
Using the Tools/Create GUID... option from Visual Studio is one way to create a new GUID, but you have to copy and paste it into the right place in your script, which, when you have to create in the region of a trillion components, can be quite tiresome.
The easiest way I've found of doing it is to create a custom macro, along the lines of:
Sub Guid() DTE.ActiveDocument.Selection.Text =
System.Guid.NewGuid.ToString End Sub
You can then associate the macro to a keyboard shortcut (Tools/Options.../Keyboard), e.g. Ctrl-K,Ctrl-G.
Creating a new GUIDs is then just two keystrokes away. (Or one if you've configured a better alternative!)