When I sit and think about how to write an argument, I put myself into my character’s shoes and approach it that way. If this were to happen in real life, how would I approach it on both sides? What are my motivations in the end? What can I say to cut someone to the bone, yet get my point across? I also read a lot, and I watch a lot of dramas. This helps me think outside of the box. Clever ways of expressing one self. I am by no means an expert either, but when it comes to heated arguments, there are many avenues you can take, and a world of resources to tap into for inspiration!