Is rehearsal important?  Odd that I should even have to pose the question, but a surprising number of the people we've worked with over the years have tried to wiggle out of rehearsing even important speeches. 

Speakers want to deliver charismatic, assured, memorable performances.  Some of them say they want to 'wing it', because thinking too hard about it or preparing too much will make them stale or boring. 

Don't believe it, and don't credit that urge in yourself if it comes up.  It's just avoidance.  It's the fear talking.  And more importantly, it's wrong.

In order to achieve the apparently effortless, natural-looking performance a great stage actor delivers, he or she rehearses for six weeks, give or take, doing the same thing over and over and over again until it has become part of not only the intellectual memory, but also the sense memory.  Professional actors rehearse all day for six weeks.  You should rehearse, at an absolute minimum, three times. 

Every speech — every communication — is two conversations, I like to say.  One is verbal, the content, and the other is non-verbal, the body language.  You need to practice both.  They must be aligned for the speech to be successful.  It takes time (and rehearsal) for the non-verbal, especially, to become easy and natural-looking.  You can't just 'think' the non-verbal side of things precisely because it's not primarily an intellectual act — it's a pre-intellectual one.  Different parts of the brain are involved than the frontal lobe, where the intellect is busy. 

I can always tell an under-rehearsed speech not only because the speaker may fumble the words, or the transitions, but because the non-verbal side of the speech looks awkward.  Winging it means that you will look like you're doing it for the first time.  Is that what you want to say to the audience?

Audiences will forgive the occasional verbal slip, but if you look like you don't know what you're doing, they'll write you off as a loser every time.

It's not about being slick.  It's about looking authentic — looking like you, not some nervous, fumbling version of you.  Rehearsal lets you get there. 

I talk about this in more depth in my book, Trust Me:  Four Steps to Authenticity and Charisma.  Give it to a public speaker you love this holiday.