In college I took a voice and articulation class. It was taught by a woman who was... nice on a certain level. And she was a good teacher in a lot of respects. But she was a singer, an actress, and a professor. That's a lot of crazy for one body to hold.
In this class I did learn that my optimal pitch was in the baritone range. That's held up pretty well. I do seem to sound better that way.
However, you kind of have to go beyond that. Good posture is, I think, important to sounding your best too. If you have your feet planted firmly on the ground and your back straight, you can summon up more energy when you need it. And it helps to take a direct approach to communication. If you're trying to pussyfoot around a subject, you could well find yourself stammering and falling back on other old habits.
It's also good to imagine that you're holding a miniature laser cannon in your hand. But now we're dealing with advanced methods...