There is plenty of information around about getting your interview ship shape. I won’t repeat the things you can find out on seek.com or any similar sites. I will focus on the soft skills and life skills side of things.
Before we start that, I just want to put the last topic about posture into the interview context.
There is never a one size fits all approach to doing anything. Do your preparation and find out what is appropriate for this industries culture. There is no point in presenting yourself one way when it is contrary to the culture. What is the message it sends to the interviewing panel. There are some general rules that you should always follow.
As an overview, think about what will build rapport and about your first 4 seconds. What will create likability?
The next topic on “what interviewers want” will give you some ideas.