How to Make a Dirty Martini
To make a classic dirty martini, start by filling your cocktail shaker about ¾ full with ice. Next, add 5 parts vodka, 1 part vermouth, and 1 part olive juice. Close the mixer and shake vigorously for 5-10 seconds. Then, strain out the ice as you pour the drink into a pre-chilled glass. Garnish your drink with cocktail olives and serve!
Add ice to your cocktail shaker. The shaker should be filled about half to three-quarters full, which will briefly chill the drink as it's mixed. Freeze your martini glasses to keep the drink chilled. If you don't have time to freeze the glasses, simply fill them up with ice water for a few minutes while you prepare everything else. Then dump the chilled water just before pouring the drink out. Add the vodka, splash of vermouth, and olive juice to the cocktail shaker. Start with the given ratio and adjust it as necessary -- roughly 5 portions of vodka, and 1 of each vermouth and olive brine. Olive brine is simply the juice that cocktail olives are stored in. Close the mixer and vigorously shake the cocktail for 5-10 seconds. Like most drinks, many bartenders have differing opinions on how long to shake a dirty martini. The longer your shake, the colder the drink will be, but coldness also dampens flavor, making this a delicate balancing act. At least five seconds is a must, and 10-15 is a good middle ground, but some bartenders shake for up to thirty seconds. Strain into the cocktail glass. Make sure you strain out the ice, as a dirty martini is never served on the rocks. This is why pre-chilling the glasses is such a big part of a successful drink. Garnish with the cocktail olive. Stab 3-4 olives onto a toothpick and let them soak in the martini. They'll soak up some alcohol and provide a delicious treat when your drink is done. Try it out a dirty gin martini. This will be a little sweeter, and often benefits from a little extra vermouth. While vodka martini's are much more common these days, there is no reason to stay tied to trends without trying out both drinks for yourself. There are bartenders who swear by gin up and down the coast in place or vodka, and those who ardently defend vodka. The thing is-- they're both right, so try both! Go for a stirred martini, not shaken,  for a little more alcoholic bite. A shaken martini actually "bruises" the vodka or gin, chilling it for longer, mixing in the olive juice, and taking some of the flavor of alcohol out. But for a drink with a bit more "umph" in it, got for the stirred martin, James Bond be damned. Consider skipping the vermouth. Sour, herbal vermouth is, in some circles, essential for any martini. But a growing legion of bartenders is swearing off vermouth, believing it is a bit too strong of a flavor that detracts from the simple, classic flavors in the drink. You can also cut the vermouth in half -- adding just a splash to get a little kick without overpowering the drink. You might add a touch more olive juice in place of the vermouth. Play around with the ratios of brine and booze to get your perfect martini. The higher quality the olives, the better the martini. But even cheaper olives will be good if you pay attention to how much brine you're adding. Everyone's perfect ratio is different, so feel free to play around until you find yours. 
Add ice to your cocktail shaker. Freeze your martini glasses to keep the drink chilled. Add the vodka, splash of vermouth, and olive juice to the cocktail shaker. Close the mixer and vigorously shake the cocktail for 5-10 seconds. Strain into the cocktail glass. Garnish with the cocktail olive. Try it out a dirty gin martini. Go for a stirred martini, not shaken,  for a little more alcoholic bite. Consider skipping the vermouth. Play around with the ratios of brine and booze to get your perfect martini. 