Serve straight up garnished with either a maraschino cherry, luxardo cherry, brandied cherry, or an orange peel.
Manhattan cocktails typically use rye whiskey which complements the sweet vermouth, though you can substitute with bourbon if preferred.
You can mix both sweet vermouth and dry vermouth for more depth or you can simply use either or.
For the best herbal botanical notes, use Angostura bitters. This is the most traditional type of bitter used in a Manhattan. Orange bitters work just as well but add a twist of citrusy orange flavor to the drink. Both of these bitters complement this classic cocktail well and are both widely used. It’s up to you!