Sure, here is a recipe for a classic gin sour cocktail using gin, lemon juice, and simple syrup: Fill a cocktail shaker with ice. Add 2 oz gin, 3/4 oz lemon juice, and 3/4 oz simple syrup to the shaker. Shake the mixture vigorously for about 10-15 seconds. Strain the cocktail into a chilled glass filled with ice. Garnish with a lemon twist or wheel, if desired. Enjoy!