Start by filling a highball glass with ice cubes. You can use as much or as little ice as you like, but make sure the glass is at least half full.

Pour 2 oz of vodka into the glass. You can use any type of vodka you like, but a good quality vodka will make a better drink.

Top off the glass with tonic water. You can use any brand of tonic water, but Fever-Tree is a popular choice among bartenders and mixologists.

Add a squeeze of fresh lemon or lime juice to the drink. This will give the drink a citrusy kick and help to balance out the bitter taste of the tonic water.

Give the drink a quick stir with a spoon to mix the ingredients together.

Garnish the drink with a lemon or lime wedge. This will add a pop of color to the drink and make it look more appealing.