Fill the copper mug up to the top with ice.
Using the jigger, measure out 2 oz of gin. Then, toss the gin into the mug.
Using the jigger, measure out .5 oz of lime juice. Then, toss the lime juice into the mug.
Using the jigger, measure out 4 oz of ginger beer. Then, toss the ginger beer into the mug.
Grab a sprig of mint and put it in the side of the drink.