The Gin Fizz cocktail has a very light sour taste that allows gin to shine through.
Pour all the ingredients (gin, sugar and lemon juice) in a shaker and fill with ice.
Shake well.
Strain into a highball glass or a collins glass with crushed ice and fill with tonic.
The Gin Fizz cocktail is ready.
Optionally put around the glass rim sugar. Cocktail Gin Fizz is equally nice with lime instead of lemon ...