According to Ketel One's website for their "Ultimate Martini," you "pour 1.5 oz. of vodka and stir it with ice in a cocktail shaker. Strain into a rocks glass over ice and garnish with a lemon twist. This can be tailored to personal taste with the addition of olives, olive brine, dry vermouth, etc." But......
Here's what I say:
1. Lots of olives please, and make it a little dirty (topped with a float of olive brine).
2. It doesn't need vermouth, in my opinion. It takes away the flavor of the vodka. And if you've bought good vodka, it doesn't need much else.
3. As previously posted (from what I learned in Bartending School), the perfect martini should never be shaken. It should be stirred, and stirred gently to not "bruise" the vodka.
4. The vodka should always be kept in the freezer so that it is ice cold and ready.
5. It doesn't need a lemon twist if it haves olives. Just give me those olives!
By the way, if you add cocktail onions, you're no longer drinking a martini. You're drinking a Gibson. And some believe a "true" martini is made with gin, but I disagree, and so would PAH-LENTY of vodka drinkers out there. I think you can have your martini with vodka or gin. It's up to you.