Every holiday season — from Thanksgiving Day to the New Year’s Day — Americans are at their philanthropic best: Charitable giving peaks, driven by altruism and a last chance to corral a tax exemption as the year draws to a close. One question that might interest donors is this: Are there strategies for giving that can make the most of the effort? The answer, along with other useful advice, comes from Katherina Rosqueta , founding executive director of The Center for High Impact Philanthropy at the University of Pennsylvania. She offered her views on the Knowledge at Wharton show, which airs on Wharton Business Radio on SiriusXM channel 111 .…