At first I’d be talking about how it’s important to keep your attitude up and my right arm would fall drastically down . . . not the right impression for the message I was portraying.
I found that Brian Tracy has videos that you can watch to learn how the most masterful speaker utilizes hand gestures. It might look easy, but when you’re in front of a crowd, it seems safe to put your hands in your pockets or have them flaying all over the place. Learn from the best.
Eye contact is a difficult concept to master at first. The standard rule is to look long enough at someone so that you know the color of their eyes. Then move on. I have found that you’ll recognize when someone is paying apt attention to you. Attach yourself to their energy and others will follow. Then broaden the scope of your attention until you have the majority of the group paying attention.
I learned from a very seasoned speaker to nod while speaking. There’s something contagious about a nod. When you start to nod at positive points in your presentation others will match your nod and you’ll gain agreement from a wider range of your audience.
There are two schools of thought based on accessibility. There are some speakers who isolate themselves from their audience, but I believe the more available you are, the more impact you will make.