Show the skill. Make the trust checkable.

Credibility is expertise plus trustworthiness. Show expertise instead of stating it (the skill on camera, teaching live), and make trust checkable (sources, public corrections, "what we don't know yet").
S Evidence: strong. Large trials or many studies, pointing the same way.
Pornpitakpan 2004 (five-decade review).
Not medical, legal or financial advice.
In The Ecosystem every framework comes with a daily action, a room that checks in, and the full library.