You'll need: Empty bottle measuring cup dark corn syrup dish washing liquid water (add food coloring) vegetable oil rubbing alcohol (add food coloring) Fill your bottle with water then pour it into a measuring cup, keeping track of how many total oz the bottle held. Then divide the number of liquids you want to stack, into the total amount of oz. That will tell you how many oz of each liquid you should pour into the bottle so that the layers are equal in size. Obviously if you want to have different sized layers, you can. When you add the corn syrup and dish washing liquid be sure to let the liquid drop straight into the container so that it doesnt touch the sides. When you add the water, vegetable oil and alcohol, tilt the bottle and let the liquid run slowly down the sides. If you pour it in too fast, it will mix with the other liquids. I don't recommended turning your bottle upside down, the colors may separate a little but it will never be as good as the original.