1 1/2 oz of Gin
1 1/2 oz of Vodka
1/2 part of Orange Juice
1 splash of Coca-Cola (or coke)
1/2 part of grapefruit juice
Fill Collins Glass with a heaping of ice. Pour in Vodka, Gin, 1/2 of remaining glass with O.J., then rest with Grapefruit. Skake, don't stir. Then add a healthy splah of Coca-cola.