Gather your supplies.
Chill your martini glasses in the freezer before starting, or fill them with ice water while you mix the drinks. Colder glasses mean colder (and tastier) martinis!
Fill the shaker with ice. Lots of ice.
Add of 15 mL of vermouth for each drink. This will make a fairly "wet" martini; if you prefer yours drier use less vermouth.
Add 75 mL of gin for each drink you want to make. You probably won't fit more than two or three in your shaker.
Stir. Your goal is to mix the two ingredients and get them lots of contact with the ice to get as cold as possible, so don't be shy. Fifteen seconds of stirring at a minimum.
All mixed up. Fit the strainer to your shaker.
Pour through the strainer into your glass.
There are two traditional garnishes you can choose from. First, a piece of lemon zest.
Use a vegetable peeler to slice off a healthy chunk of lemon zest.
Twist and squeeze over the drink to get the flavorful oils out, rub it around the rim of the glass, and then drop it in.
Second choice (my preference): olives. If you really like the olive flavor, make your martini "dirty" by mixing in a little bit of the brine from the olive jar.