I am using a Mac--which is running OS X 10.10.3. I want to add a 'new file' button to the context menu--the menu that pops up when you right-click in a Finder window/on the desktop.
That can be done using Mac OS X native app Automator. Firstly, learn how to use it with that guide:
Now, follow this tutorial to create the 'New File' button:
Use an empty file has your template; you may call it 'Untitled' for example. You can also assign a shortcut to it going to Settings -> Keyboard -> Shortcuts -> Services. That was my reference to this information:
I know that probably you wanted the button directly in the context menu, while Automator add it inside the Services tab. In order to do that, follow these instructions:
I think that's the best you can do. I hope these instructions are enough.