Take a look at this video from Mike White, CEO of DirectTV video message to customers about the Viacom battle.
You can tell he's been coached and he's trying to implement the coaching, (ie: slowing down to emphasize his point, being more dramatic, using body movement to enhance his impact.) but Mr. White clearly over does his head wagging gesture.
We ran this video through our eye-contact measurement system and sure enough, Mr. White only registered direct eye contact about 66% of the time, with most of the remainder of his eye contact being characterized as "indirect." This is a strong deviation from our executive average of 80% eye contact and our audience tested preference of 92% eye contact.
The lesson here is to listen to coaches, but be careful to avoid being too deliberate or obvious with their suggestions. The best speakers are highly coached and highly practiced, but the true skill is making it appear natural.