So the first step is to create a new module in Visual Studio
By default the following files below are you created for you when a module is created, you can go ahead and delete the "Sample.txt" file as we will add our master page shortly.
You can down download a fantastic starter master create by Randy Drisgill from the following link.
Once you have downloaded the master page, add the master into the module.
Now once the master page has been added - open the "Elements.xml" file and add replace with the following:
Happy Branding :-)