Step 1

Rub a wedge of lime around the rim of a martini glass. Pour some of the sugar onto a shallow plate and then dip the rim of the martini glass into the sugar to coat the rim.

Step 2

Add the vodka, triple sec and lime juice and 2 1/2 teaspoons of sugar to a cocktail shaker filled with ice. Shake well and then pour into the rimmed martini glass.

Step 3

Garnish with lime wedges and serve.