Rule 11: Treat Each Co-Worker Like He or She Is Your Best Client. By Dan HullSeptember 16, 2007February 27, 2025Uncategorized In our 12 Rules of Client Service, this one, Rule 11, is perhaps the hardest one to achieve. The Driven and The Motivated–at least the able and confident ones–want people just like them in their workplace. This is admirable, and can cause problems.