Use Your Debate Opponents Own Words Against Them

Much harder to do and usually this requires a history debating a person and a good memory to recognize they are being hypocritical. If you have the time though, you can search a person's posts on Facebook, Reddit or a discussion forum for the topic or related topics you are debating about and see what they said about an issue in the past.

The best tactic here of course is to just repost their same words as if they were yours. And then if they respond, you know what to do next.

The idea here is that right-wingers are very susceptible to hypocrisy because their beliefs are primarily to dutifully support whatever the media and politicians tell them to. So, they strongly defend the Iraq War until Donald Trump becomes President for example.