Pour 1.5 ounce of vodka over ice, in tumbler, add 4 parts grapefruit juice, Stir. Dash 1 to 2 tablespoons of grenedine over top (to suit, and sweetness), then garnish with lime. Try raspberry schnapps instead of grenedine for a different kick. The grenedine should be allowed to trickle down over the drink, hence the name "sunset".