Keep it simple
There is a natural tendency to overcomplicate things, which can quickly be a distraction (and efficiency killer) from the goals of a project, a meeting, a team, etc. Resist that tendency and look to simplify wherever possible and as much as possible.
A big key to efficiency is reducing the cognitive overhead required. Is the communication clear and succinct? Can the system (or components of that system) be grasped quickly? Does the goal of the project make it clear why it’s important?
It’s easier to make something complex (usually as a result of haste, but other times as a result of laziness or cleverness) than it is to simplify. But it’s exponentially more efficient to operate when we do the work to make the complex simple.