Do not rush the layers; each should be mostly set but still tacky before adding the next to prevent blending. Cool gelatin mixtures before pouring to avoid melting the previous layer. Pour over the back of a spoon to slow the liquid and prevent mixing. Keep the knife warm and clean for smooth cuts. Sweetened condensed milk is key for the creamy white layer and helps bind layers. Use neutral-flavored vodka for balanced taste. For non-alcoholic versions, substitute vodka with cold water or fruit juice. Store covered in the refrigerator and consume within 3 days for best texture.