Ten Ways to Keep and Get Clients
Realistically, it will be impossible to keep every client due to any number of factors; the marketing director you've worked with for years leaves or another design firm offers a 'loss leader' project. While some scenarios are out of your control, many are not and taking a proactive stance can do wonders.
Schultz, Derald. Creative Latitude (2005). Careers>Freelance>Graphic Design