The most fundamental thing to remember about branding.
...is that it is a form of method acting. You have to actually breathe, eat, sleep, walk, and talk the brand. But know it is always a brand and not real.
That is critical - the capacity to step back and observe, reflect and recalibrate. To orient everything you do toward a specific, focused, rational goal.
Reposting my answer from Quora. All opinions are my own and do not represent those of my agency nor the federal government as a whole.