It is one thing is to know something intellectually and another thing is to actually do it, and do it consistently.
This applies to public speaking skills, too. “Doing it” consistently is what matters.
Several years ago, when I was teaching a public speaking class, a few of the participants remarked, "we already know this stuff." However, when I watched their presentations later that day, it was clear that even though they claimed to know “this stuff” about the fundamentals of good presentations, they hadn’t practiced it consistently.
Instead, their presentations were full of filler words, (like "um" and "ah"), the organization of their information was jumbled and hard to follow, their slides were overcrowded with too many words in tiny font and their message was vague.
In order to be a good presenter, you have to go back to the basics of presentation content and delivery. Master these basics through repeated practice and feedback, until they become a regular, consistent part of how you present. Then you’re ready to say, “I know this stuff” and “I do it.”
For a review of the fundamental building blocks of good presentation skills, check out my articles: