What Makes an Authoritative Writer?

It is important to make sure your readers realize that you know what's what in your field. What you write doesn't matter as much as how you write it.

There are ways to make an authoritative impression:

Be bold and confident when you state a point of view.  Do not introduce your views with "I think" or "I believe". This only makes you seem tentative or timid.  Being somewhat controversial or surprising helps.

You should always support your points with data and trustworthy sources of information. Find little-known examples, and links to other areas of knowledge. The result will be you come across as a grounded, insightful expert rather than a pitchman.

Use a direct, punchy writing style. Use short sentences and clear vocabulary. Drop empty adjectives (such as "awesome," "killer" or "terrible").

Correct your errors. You can destroy your impact if you allow in typos or factual flubs. 

Write about subjects that are important to your audience. Follow the above stylistic points and be relevant to your audience. You will earn respect and followers. Over time, your authority will build your reputation. You will stand out as a leader, not another random promoter.