2 ounces vodka
1 ounce cranberry juice
1 ounce Cointreau or Triple Sec
1/2 ounce lime juice
1/2 ounce simple syrup

Shake with ice. Strain into a cocktail glass. Optional: Before pouring the drink, you can moisten the rim of the glass with lime, then coat with sugar. Some people also add finely grated zest of orange to the sugar used to coat the glass with. A dash of Orange Bitters also works really well with this cocktail.