I receive this question regarding the most effective manner of hand gesturing for a speaker.
Before I answer that, let me ask you a question. What's the purpose of your speaking? I hope it is to serve your audience. And if you were going to serve someone you card about, how would you do it? With your palms up and your arm slightly extended. Right?
Depending upon what you are saying or the emotion you wish to convey, consider leaning in a bit.
I've included a few illustrations that should help.
There's lots more to talk about such as