This video from design group Kurzgesagt offers up a simple method on how to debunk conspiracy theories. They explain:

Most Conspiracy Theories are stupid. By the power of the internet they spread like wildfire and often poison discussions. But there is hope – we developed a way to debunk conspiracies in just a few seconds…

Of course as a self-confessed fan of conspiracy theories this approach is way too oversimplified for me and does nothing to debunk the theory that Arnie murdered Lord Lucan.