I had patient in their mid 50's with a nearly 90 pack year smoking history (2-3 packs a day since they were a teenager) that wasn't interested in quitting smoking because he thought he would rather die of lung cancer than dementia like his mother did. I spent a good chunk of time explaining how smoking can actually increase chances of dementia, and how much the health consequences of heavy smoking suck. He already had the early stages of COPD and explaining how much worse it could get made it make sense to him.
I had a childhood friend that died from cancer that metastasized to his lungs and my grandmother died from severe emphysema leading to respiratory failure. Amazingly, getting someone to understand that what they're doing is going to result in slowly drowning in their own lungs as they lose surface area and fill up with fluid and tumors really turns on a light-bulb for them. The vivid description of a person gurgling with each breath and the reality that this went on for months or years until it finally killed them was a good illustration. I made good use of my humanities degree where I learned how to use descriptive language to make a convincing argument for this one. The patient did end up agreeing to getting meds to help with quitting and information on support groups to help with it.