My rule of thumb in work, especially as a consultant is to manage huge projects in simplified stages.
This was an idea after seeing how smaller, more detailed projects are carried out. When there are many people, ideas, initiatives, and specialties revolving around a marketing plan (or whatever massive plan you are working on) try and segment as such.
Ideate--create all of the necessary scenarios and options your situation involves. Make a plan to achieve your benchmarks and express yourself completely.
Dedicate--each individual working on this project knows their limitations. They also know what the goals are. Unfortunately, many people find it difficult to do little tasks while keeping the bigger picture in mind. Keep the team on track.
Elevate--it's not easy completing projects from scratch. It's in our human nature to become invested in our work and feel the emotional tugs that a project's tumultuous "peaks and pitfalls" ultimately brings. Make sure to keep everyone motivated.
Appreciate--making it to the end of a long and detailed project require a lot of flexibility and honesty with yourself and your team. More strengths and weaknesses get recognized as work happens and it's important to remember the good that people do more than the bad or inconvenient. Make your team feel worthy.