Few thoughts..
First You have to always smile..and look him in the eye..and speak to the camera..
As for calling out lies...I have found you can tell anyone just about anything as long as you do it with a smile and avoid over the top remarks..
"Well there you go again, Paul!" Might be good to take Reagan's famous line and use it against them! Not too aggressive but effective
And I would try to reduce their lies to the absurd..
" So let me see if I have heard you correctly...you would have us believe a big spending democratic President who has no concerns about the deficit and who will do anything to get elected, has just robbed his most important constituency of 750 billion dollars in Medicare payments in the middle of a close election? Is that what you are saying, Mr Ryan?"
You say President Obama has eliminated work rules for welfare? So you're saying that is what Governor Romney did when he took part in a similar program in Massachusetts, arent you?
"So you think the real problem with America is the rich need more money and corporations need more power?"
Mr Romney has said sick people can find health care in the emergency rooms..Ever hear the old saying " an ounce of prevention is worth a pound of cure.."
And don't be afraid to attack..forcing him to spend time defending himself and his record...while pointing out how your policies will benefit the middle class and his will not..and smile and laugh as you do it...
Just a few thoughts..hope this helps and here is a good example of humor as a weapon
Hope I have helped.. I am sure others have ideas of their own