What convinces is conviction. Believe in the argument you're advancing. If you don't you're as good as dead. The other person will sense that something isn't there, and no chain of reasoning, no matter how logical or elegant or brilliant, will win your case for you.
“My girlfriend Siri is a food blogger, and we both love to entertain and eat. This is what happens when you're in your thirties: what was once a passion and real appetite for nightlife in New York City manifests itself into other things, like entertaining at home.”
“Never before in modern times has so much of the world been simultaneously hit by a confluence of economic and financial turmoil such as we are now living through.”