Just be creative & have fun!
So, let's pretend we have a tag open in front of us.
That way the edges of the mask are coming out from beneath your tag adding extra color.
It also gives it a nice, finished look once the rest of the tag is done.
0wqYou can also use it as the main part of your tag, or in other ways.
But not today, for today it will be on the bottom layer.
Add a new raster layer and flood fill it with a color, patter, paper or gradient of choice.
That will move your layer to the very bottom, which is where we want our mask to be today.
Ours today is 'DD-NFM-2015-2'