Here's how to do it:
Equipment: The classic mug (though not required) and a stirring rod
Ingredients: ½ oz Lime Juice, 2 oz vodka, 4-6 oz of ginger beer, ice cubes
Do this for 1 drink: Squeeze lime juice into a Collins glass or Moscow Mule mug and drop in the squeezed out lime shell. Add 2 or 3 ice cubes, then pour in the vodka and fill with cold ginger beer.
If you’re feeling fancy: Serve with a stirring rod.
Adapted from a recipe here.