Preach the Need for Change, but Never Reform too much at Once

Everyone understands the need for change in the abstract, but on the day-to-day level people are creatures of habit. Too much innovation is traumatic, and will lead to revolt. If you are new to a position of power, or an outsider trying to build a power base, make a show of respecting the old way of doing things. If change is necessary, make it feel like a gentle improvement on the past.