Take ten minutes right now to do this exercise.
First, imagine something has happened and you won’t be in your office for the next six months. Then write a letter providing instruction and advice about what needs to be done during the time you’ll be gone.
Second, compare what you wrote to what you have already communicated to key people in your organization. Ideally, you have already communicated these things. If you haven’t, schedule when you’ll do the communication.