I think the more you do, the more comfortable you get. The very first vlog I did, I took it 17 times!!
Now, I usually get them done in the first try, sometimes the second.
I just use my Flip Camera, it's working fine for now. I do try to make sure the lighting is good too.
I also always run thru the video with my son who is taping so he knows what I'm going to be talking about and which direction to point the camera.
We use a tripod too, which helps alot!