I keep mine to three — Integrity, Growth, and Results. I read somewhere that anything beyond three usually collapses back into one of those anyway, so I'd rather have three I actually live by than seven that sound good on a wall.
Integrity: I recommend what's right for the lawn, not what's easiest or most profitable for me in the moment.
Growth: Constantly improving methods and equipment, and helping homeowners understand their own lawns so they get better results.
Results: Judged by actual outcomes over time, not promises. Conditions and follow-through matter, and I build my plans around that reality.
I'm solo right now, but these are the same standards I'd expect from anyone who eventually works under me.