Joel has broadened things and allowed for splitting of spirits and modifiers in this month's MxMo. I for one am sticking with vermouth. I thought it a shame that I'd already used the Perfect Cocktail once before until I stumbled upon Bitter Sweet, that is. You may find differing recipes or ratios (such as at cocktaildb.com) but I wet with the recipe in Schumann's American Bar.
1 oz vermouth rosso
1 oz dry vermouth
dashes of orange bitters
Stir; strain; up; twist
I used Carpano Classico and Dolin Dry. I also used New York style "50-50" bitters. Use the clearest ice you can acquire. Stir "gently and extensively" in a mixing glass filled with cubed and cracked ice. Perhaps use the method found in The Bar Book. Perhaps useThe Speakista Martini Method. Be sure to chill your coupe while assembling and mixing. Strain as if your name were Fluval. Rub the peel around the rim of the glass, if you enjoy such things, before adding to the drink. Enjoy! Then have something to eat.