When Pat Woertz became the CEO of ADM in 2006, the management challenges she faced were subtle. "It's very difficult, I think, in a company that's not failing to get people's attention," she said at the 2008 Fortune Most Powerful Women Summit. Her advice? Stay on the edge of your seat, even if it's tempting to lean back. "When things are going well, leaders should probably be the most paranoid types... looking over our shoulder and worrying what's on the next horizon."