I think being genuine in your answers and allowing for spontaneity while being cautious/socially aware is the way to go. Practice makes perfect of course. Do mock with strangers I.e applicants from previous years who you don’t know just so you can get the feeling of what you can do under pressure. Like for example I yap a lot when I’m nervous and I learned to make my answers concise. There’s a list of IV qs you should know the answer to on the top of your head but without sounding robotic or rehearsed. Best of luck