While hanging a 8-story picture of yourself on a prominent building in town is one way to proclaim your authority, there are easier tactics.
Speaking with authority does NOT mean you are authoritarian or dictatorial, although you might be, from time to time. 😉
Speaking with authority means you know what you’re talking about. It does not mean you are the world’s expert on your topic, although that’s not a bad thing to be. You do, however, know more than your audience about your topic.
It is not only important to know your topic, you also want to look like you know your topic. You want people to take you seriously when you’re presenting.
Many of my clients are not used to thinking about speaking with authority; they’re used to getting the job done, often working behind the scenes.
Sometimes I work with a client who is highly suspicious of coming across as pushy or overbearing while trying to speak with authority. Thinking in terms of authority or ineffective is a dangerous false dichotomy.
I like to emphasize a natural and quiet confidence when working with most of my clients; they’re not the cheerleader types nor do they wish to be.
In preparing your talk, remember what makes you an authority on your topic. Think about what an authority figure would look like and sound like. Now you are the authority.