It'll be so obvious if you read or memorize a script. Even more so if you're not a native English speaker.
Just try to exercise the stories you're trying to convey in your head or in mock interviews.
It's like basketball. When you practice alone, you practice shots, lay ups and dribbling repetitively. Once you do that, those moves will naturally come out when you play the real game, in which conditions are more unpredictable. If you just try to repeat those moves like a robot, you'll end up making yourself look like a clown.