Public speaking is at the same time an art and a skill. There are skills some of us are born with but there are others we can develop, public speaking is one of them.
It's true, some people find it easier to stand in front of a crowd and speak without any problem and to others is their worst nightmare.
But the real deal is that we can achieve everything we propose and if we try it, follow tips like these @wcy and the key is ro practice. Practice helps us mastering anything we want. If we focus on that skill, we can master it and you'll see you can be speaking in front of thousands as you speak in front of your family.
Great article by the way!!!!