How does Shakespeare use metaphors to create a heightened sense of drama in ‘Romeo and Juliet’?

1. 'Love is a smoke made with the fume of sighs'

Shakespeare uses a conceit here (an unsual comparison between two things) + Semantic field of suffocation/pollution + olfactory imagery = dramatic because it poses Love as something dangerous and toxic but also slightly undetectable - little foreshadowing here as Romeo actually poisons himself due to his love

Love is an abstract concept + 'smoke', 'fume' + onomatopoeia 'sighs' = things that are intangible which connotes that love can be difficult to grasp