Oh my lord almost the entire thing is a series of devises, especially irony.
A very obvious example you'd be advised not to use: the irony of Romeo's sacrifice, drinking the poison to be with his love, only to be the cause of her demise. Very poetic.
Another example of irony: The Montague's and Capulet's determination to keep their children safe from the other family, only to drive them both to their graves through increasingly hateful acts.
Honestly the entire story is riddled with irony. Pick a situation where a character makes a choose that ends up doing the oppositite of what they intended.
