Now, practice, and being out of our comfort zone are not mutually exclusive the way I see things. In fact, by practicing you get better at handling the camera, understanding light of all kinds, , instantaneously compose an unknown scene, reacting to the subject matter, and 'feel' the whole workflow, from exposure to finished print. And that makes you prepared to react to something that's completely out of your comfort zone.
So, to me, the more you practice and the more you shoot and print, the more able you will be to simply react to what's in front of you, focusing only on the subject matter, without having to think too much about work flow.
I have noticed this lately, where I basically have no time to print and shoot, so I find it a lot more difficult to be in tune with my work flow as something good comes my way; I basically feel out of practice, like a runner who hasn't run for a long time, and is trying to get back into shape.
That's what I think practice does.