I suppose that my biggest thing is good analytics and figuring out what your specific KPIs will be for a specific site. After figuring out the best KPIs, work on those, don't get distracted by keyword rankigns, those can change all to easily when Google decides to chagne the ranking algorithm.
Focus on why we want rankings: to get converting traffic. If you're spending hours or days working on something, it had better effect the bottom line for the company or it isn't woth doing.