Technique
Layer
To layer a drink is to pour its ingredients one at a time so each sits on top of the one below, giving separate bands of color.
In practice
Pour the heaviest liquid first, usually the sweetest one with the least alcohol, then pour each next one slowly over the back of a barspoon. Layered shots like the B-52 work because sugary liqueurs are denser than spirits.
Drinks to try it with
Layer, in short
What does layer mean in cocktails?
To layer a drink is to pour its ingredients one at a time so each sits on top of the one below, giving separate bands of color.