By communicate I mean to convey what I want to say with the appropriate style and manner so that I don't say anything that sounds demeaning or hurtful to the listener. It also includes listening attentively to what the other person is saying.
How to learn all that?
1a. Fewer words are more powerful than many. Attempt to reduce your word count as much as possible.
1b. Expand your vocabulary.
1c. Make your statements active, not passive (reduce or eliminate 'be' verbs).
1d. Plan your thoughts well and orderly.
1e. As much as possible write in a narrative style.
1f. Speak from facts. Clearly state when your opinions are your opinions. Leave nothing to chance. Nobody will assume your expertise and generally nobody cares.
1g. In all things execute with precise.
2. Speak like slow, clear, deliberation like your mastery of writing.
2a. Speaking is plumbing. The words that escape your mouth are sewage. You don't them back and you don't want to. Keep a solid rhythm so the plumbing does not back up.
2b. Speak from empathy.
2c. 90% of communication is non-verbal comprising tone, facial expression, and body language. Embrace this.
2d. Make all communications flow from logic, but remember all communications are emotional all the time.