Chill martini glass in the freezer or refrigerator. Put ice in a shaker, pour gin and vermouth over the ice and shake. Strain into a chilled glass and garnish with a lemon twist.
Notes
Make no mistake. This is jet fuel. It's an acquired taste that suits those dedicated to obtaining a goodly buzz without the calorie cost of mixers or the hangover messiness of sugar syrups and real sodas. One will do you. :)