Fill the cocktail shaker with 2/3 of the way full of ice. Pour in enough margarita mix to cover the ice, put the lid on the shaker, and shake vigorously for 10 seconds.

Just grab a bit of margarita mix (and other margarita essentials) and that can of condensed milk sitting in your pantry. A few easy steps later and you've got a creamy frozen mousse good enough to ...