Layering liqueurs is not hard; you just need to check the weigh of each liqueur. Each liqueur has a different weigh and either floats or sinks when poured onto another.
To create the drink, pour the liqueurs into a glass, use the back of a spoon and rest it against the inside of the glass pouring slowly into the glass. The liqueur should run down the inside of the glass and layer. Make sure that the liqueurs are poured in order of their weight, starting with the heaviest first. Otherwise you will get a messy (muddy) drink.
If you do not know the specific gravity of liquor or a liqueur, they can compare the proofs on the bottles. The Lower proofs of liqueurs generally have more sugar and the liqueur is thicker and heavier.
