POUR GIN, VERMOUTH AND SYRUP INTO A COCKTAIL SHAKER WITH ICE. SHAKE VIGOROUSLY FOR 15 SECONDS. LEAVE THE SHAKER AS IS FOR 30 SECONDS TO A MINUTE, THEN STRAIN INTO A CHILLED MARTINI GLASS AND GARNISH WITH A MARASCHINO CHERRY (THE ROSÉ VERMOUTH CAN BE REPLACED WITH ROSÉ AND THE STRAWBERRY SYRUP WITH ANY OTHER BERRY SYRUP.)