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.
All mixed up. Fit the strainer to your shaker.
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.
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.