Note that these ideas are not fully worked out (except for the last one).
Emphasize the strengths and diversity of Obama’s experience compared to McCain’s. For example, paint McCain as a Washington Insider for over two and a half decades, becoming more out-of-touch with ordinary Americans year-by-year. Washington Insider. Rinse, repeat. Compare that to Obama, who during McCain’s early years in Washington (maybe mix in a little Keating for good measure) was working as a community organizer in some of the poorest neighborhoods in Chicago. No one has to tell Obama what it’s like to struggle day-to-day wondering whether you’ll be able to pay the bills. He’s been there shoulder-to-shoulder in worse situations than most of us have experienced. When he is President, that experience will guide his economic solutions – he understands what those of us making under $5M/year are going through :). This dovetails nicely with Housegate or whatever we’re calling it.
Frame the European trip positively as a national security issue. McCain has embraced the Bush policies that have led to the US extending its military and becoming isolated from its allies. What happens if a situation occurs where we need serious military help? The next President needs to be able to bring the people and leaders of our allies back into the fold. Obama has already started doing that. I can imagine a commercial showing a collage of world leader head-shots with Bush and McCain in the middle, and as the narration is read, the heads slowly fade away leaving Bush and McCain isolated. Compare to a large crowd embracing Obama. Who do you want making that call for help?
Always refer to Cindy McCain as John McCain’s second wife. It won’t make a difference to someone like me, but with enough repetition it will affect some voters.