If you have time, chill a large martini glass in the freezer for at least 15 minutes.
Fill a mixing glass or cocktail shaker with ice cubes
Pour the vodka, Cointreau, lime juice, and cranberry juice over the ice. Cover the glass and shake well (you can also give the cocktail a good stir, let it sit for 30 seconds, and stir again, repeating once or twice more.
Strain the cocktail into the chilled glass. Garnish and serve.
Notes
To flame the lime or lemon zest strip, hold the strip of zest over the drink. Light a long kitchen match and warm the strip over the flame so that a drop or two of oil falls into the cocktail. Drop in the zest and serve.