Grab some ice and toss it into your highball glass.
Grab your jigger and Gin. Use the jigger to measure 2 oz of Gin. Toss that into your highball glass.
Grab your soda water. Use the jigger to measure 4 oz of Soda Water. Toss that into your highball glass.(note: you can add more soda water if you prefer a less strong Gin taste).
Use your bar spoon to lightly stir the drink together.
Grab a lime and cut it into slices. Cut a notch in the pulp of the lime. Add the lime to the rim of your glass.