Combine vodka, Grand Marnier, sweet-and-sour mix, and cranberry juice in a shaker.

Add lime juice to the shaker.

Shake well until chilled.

Strain into a chilled martini glass.

Slowly pour a drop of grenadine into the middle of the glass.

Let the grenadine fall to the bottom to color the stem red.

Garnish with a lime wheel or lemon twist.

For the sweet and sour mix: Combine sugar and water until sugar is dissolved.

Add lemon and lime juices to the sweet and sour mix.

Refrigerate the sweet and sour mix.