If you have an important presentation coming up... heck, any presentation coming up... you know you need to practice.
But what sounds perfectly rational, smooth, and compelling inside our heads... isn't always rational, smooth, and compelling when it comes out of our mouths.
So you NEED to practice OUT LOUD.
There are ways to strengthen your practice (and increase your ability to review for effectiveness):
But at a minimum... it needs to be out loud. Or it doesn't really count.