I’ve always said the number one thing you can do to improve your public presentations is to rehearse. A lot. And not just the opening, or that crucial bit in the middle. All of it. Or as Tim Sanders says: All. The. Way. Through. Complete with bold emphasis.
So is rehearsal always a good thing? Surprisingly, no. Check out Sanders’ article on the times when rehearsal is not called for. Hint: it doesn’t take place onstage.