Here is the process I use in both personal and professional lives.
Start with a little planning. What is the message you want to convey? What information is needed to be shared? Who do you need to include on this?
Once the initial plan is figured, then I move on to the body. I am not a fan of super long paragraphs and complicated messages. Stick with one topic, short, brief, and actionable items. I call this bullet to speak. Create an introduction is the issue. What is the justification, and then what is the task or action needed?
Bullet speak does not mean make it full of acronyms. Spell it out and make it clear. See Elon Musk’s May 2010 email to SpaceX called acronyms seriously suck. The acronym for this email is ASS. I use them only if they are industry standards. For example, DB for a database is standard for DBA but not for Information Technology as a whole.
Images should be used only when required. I like to keep this to screenshots where the reader would get lost in the email without it.
In Emails, icons are used sparingly also. I avoid GIFs (animated images) altogether.
Sound, never use it unless your email is about sound.
Bullets and lists I use but mostly in a list of steps and a list of issues to be discussed or, better yet, an agenda.
Next, I summarize the message in the subject line. They are no more than 10 words to get the recipient to read the message.
Who to address this email to? The police, fire, and military, I would say your direct boss only. I use the method of my direct boss in that area for the first attempt. Then the second attempt if their boss assumed I did not respond on the first attempted email, and I am required to continue to chase this further. Additional recipients would be other people that will take action on this topic. If the additional recipients are only readers, then use the Carbon Copy.
The Carbon Copy (CC) are people that are in the maybe read category. Those who don’t need to take direct action but need the information on this subject. I really try to keep this group as low as possible. Be careful not to give out an email address when not needed freely. This promotes spam emailers. Blind Carbon Copy is not a solution for this either. Just don’t include others in this email.
Blind Carbon Copy (bcc) should only be used as protection from the crazies of the world. Professionally, I think I have only used this 2-3 times in 20 years. I will use it to protect your email address from getting exposed to other people.
When should your email be a phone call? When your reaction time requirement is nearing immediate, or you have a deadline you are working under. With vendors, I like to use all emails, so I have a trace of the conversation. Everyone is busy, and emails can be handled when they have time.
When should your email be a meeting? I like a face-to-face meeting with co-workers because it creates priceless training opportunities. But in general, if the issue is complex or when a dialog is required, then have a meeting. Meetings take longer than 30+ minutes, and a limit to specific times makes them far less desirable than emails.
Communication is the hardest part of IT, but if we work from the same set of rules, it becomes a little easier and more effective. Frankly, I want all our jobs to be a lot easier. How can I help you work more effetely?