Written communications should be interesting to assure they will be read. The communications should avoid ambiguity and jargon that might be misunderstood. Common words should always be used unless more exact words are needed for definition. If you use words that everybody knows, then everybody can understand what you are saying. Communicate as much information as it is possible.
Lack of communication breeds rumors and rumors destroy morale.
Always tell the truth in communications. Dishonesty will destroy integrity and confidence. Be very careful with ministerial estimates. Cultivate feedback from the followers. Feedback can give a mental and emotional response.