1. It matters more whether or not an opinion is correct or a thing is good than whether or not it is held/used by the most oldfags or it's a norm of somewhere. If it's a subjective matter then you still shouldn't believe or do something simply because the people around you believe or do it or it's a tradition.
2. Don't use ad hominem. Example: "Go back to <place I don't like> you fucking cancer" on it's own. Instead you should explain precisely why they are wrong.
Any more?