Chill martini-type cocktail glasses. (Three ice cubes and a shot or two of water will get the job done quickly.)
Put several ice cubes (not crushed) in a pitcher, or a large glass tumbler.
Add bourbon, vermouth, and bitters per the recipe.
Gently swirl or stir for at least 20 seconds.
Do not hurry this, and absolutely do *not* shake it.
Strain into chilled cocktail glass.
Add stemmed maraschino cherry.