Add vodka, grapefruit juice, Cointreau to a cocktail shaker. Fill with ice.Shake vigorously and pour into martini glass. Stir in one teaspoon of honey, if desired.
Garnish with a grapefruit wedge. Serve chilled.
Notes
The better the vodka, the better the drink. I usually use Ketel One for my martinis.You can substitute gin if you prefer a gin martini.