You may want to review these rules before you start writing. They can also be used to create an outline to guide you in your writing. After 35 years, I still refer to these rules when I need a tool to help me get unstuck.

1. You must have something to say. 
2. You must have someone to say it to. 
3. You must say one thing at a time. 
4. You must say things in the right order.
5. You must write in a concise matter. 
6. You must adhere to the facts and tell the truth.   

Consider the rules again as you proofread and edit. 

Details are as follows - 

Rule 1. You must have something to say... 

KEY MESSAGING  

Many write reams without saying anything at all. Don’t confuse or bore your readers with long, wandering passages. Do not bury key points. Highlight them. Get to the point so your reader understands. Draft a quick outline of key points. Decide on key points and not your personal preferences. Stay focused and follow through. Note: I often write one sentence about my key point and type at the top of the first page so I don't stray.

Rule 2. ...and someone to say it to. 

TARGET AUDIENCE  

Be considerate of who you are talking to; your writing style and messaging should fit your audience’s expectations. Your reader is your first priority. Your content, writing style and tone should reflect that. Questions you should ask: is your audience internal or external? Are you writing for employees or are you writing for the public? If writing for the public, exactly who is the target? Drill down, research what has already been said to this target on the same matter. What was the response? Imagine what that audience needs/wants to hear. 

Rule 3. Say one thing at a time. 

COMPREHENSION  

Reading is a form of intellectual ‘digestion’. People can only consume so much content at one sitting. If you write sentences and paragraphs that are too long and with too many messages, it is likely your reader will give up trying to understand and abandon your pages. The same thing may happen if your reader hits a typo. To be read and understood, you must develop one key point per section using short, concise sentences. 

Rule 4. Say things in the right order. 

LOGIC  

Prioritize the facts and position with meaning. The most important information leads the way. Order enables our understanding. As with a fine meal, dessert is last. You might think about that sweet finish as you organize your information. Logical order is sensible, traditional, easy to understand. 

Rule 5. You must say things in a concise manner. 

TECHNIQUE 

Boil it down. Write, then rewrite. Proofread your own writing with accuracy and precision. Review with fresh eyes. A sentence should run no more than three lines. Paragraphs run 10-12 lines long. Stay on point. Don’t overwrite. Don’t wander. Don’t inject personal opinion or quips. Avoid overly tight sentence structure and clever phrasing. Stick to the facts and get to the point quickly with as few words as possible. 

Rule 6. You must adhere to the facts and tell the truth.  

ETHICS  

Opinions are interesting but aren’t always based on unbiased fact or validation. Conducting your own research is the best way to confirm accuracy. The quality of your research will also affect the thrust of your argument. This is not to say business writing must be void of passion. On the contrary. Fact can make a very strong, emphatic case. Plus, facts are more credible than opinion and help readers understand and accept your point.   

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Source: An Alberta Government contract writer and communicator, based in Edmonton, led an evening course On Writing Effective Reports. This was in the early 1990s. He shared these rules then gave out his card saying anyone could call him for advice any time. I called him while working in my first job as a magazine editor and will never forget how grateful I was for his support and kind understanding. KH  

Want more? Here are lists of writing rules from some of the greats. https://www.writingclasses.com/toolbox/tips-masters/george-orwell-6-questions-6-rules