See Startup Folder.

There is a Startup folder for Word and one for Office. Templates in either become "global templates." I prefer working with the Word folder because it is somewhat more available to the user. Its location can be set or changed under Word options.

One thing about using global templates instead of hard coding in normal.dotm is that if something goes wrong it is relatively easy to undo. You just move the template out of the Startup folder and your modifications are gone.

You can also load or unload global templates using code. I have one that conceals the buttons on the Reviewing ribbon that I seldom use. I have code that unloads that template (revealing the rest of the Reviewing ribbon) when I need it. That toggle code is triggered by a custom button also on the Reviewing ribbon.