Chill your glass: Place a cocktail glass in the freezer or fill it with ice water while you mix the drink.
Mix: In a mixing glass, combine the rye or bourbon, sweet vermouth, and Angostura bitters.
Stir: Add ice to the mixing glass and stir for about 20–30 seconds until well chilled.
Strain: Discard the ice from your chilled cocktail glass and strain the drink into it.
Garnish: Drop in a maraschino cherry and serve immediately.