If you're going to use a document over and over again, it makes sense to turn that document into a template. A template in word processing terms is a document with some settings already in place.
A template is a document type that creates a copy of itself when you open it. You can create a template saving a document as a .dotx file, .dot file, or a .dotm file (a .dotm file type allows you to enable macros in the file).