Combine all ingredients in a cocktail shaker with cracked ice and shake well. Strain into chilled cocktail glass.
Rub the lemon twist around the rim of a chilled cocktail glass and discard the peel. Combine gin, vermouth, and olive brine in a cocktail shaker with cracked ice and shake well. Strain into chilled glass and garnish with olive.
Combine liquid ingredients in a cocktail shaker with cracked ice and shake well. Strain into a chilled cocktail glass and garnish with olive.
Place gin, vermouth, olives, cocktail glass, and cocktail shaker in freezer for at least 3 hours. When all components are thoroughly chilled, combine gin and vermouth in the chilled cocktail shaker and shake well. Place the two frozen olives in the chilled cocktail glass and pour the gin and vermouth mixture over it.