To start off I think that a clear message is vital: embracing both a problem and a solution. Whenever I have been running a campaign, which has really been on a roll, there has been a very clear message or elevator pitch that not only my colleagues and I have been using, but all people supportive of the campaign. There was no ambiguity at all about the message; indeed I like to talk about the importance of an absence of ambiguity in campaign messages.
I also think that a clear understanding of the problem is vital. Now I have launched some campaigns with no clear evidence just a sense of outrage, but we have always then gone onto collect the evidence to justify and energise our campaign. The more that I have built evidence for campaigning, the more that I have liked the macro/ micro approach; whereby I mean you collect both big picture statistics (ie: the number of people destitute) as well as the individual human stories (ie: individual people’s own account of being destitute). I feel that this combination can be compelling for effective campaigning.