Pick the target, freeze it, personalize it, and polarize it. Cut off the support network and isolate the target from sympathy. Go after people and not institutions; people hurt faster than institutions. (This is cruel, but very effective. Direct, personalized criticism and ridicule works.)
Rules for Radicals: A Pragmatic Primer for Realistic Radicals (ed. Vintage, 2010) - ISBN: 9780307756893