I’ve had a few group interviews. I think an important thing is to be yourself, because in a group it’s very easy to spot someone who is trying too hard/faking it, e.g. answering ‘I work too hard’ as your biggest weakness would come across as even more inauthentic in a group interview than usual. Otherwise, practising your answers for common questions might come in handy in case someone has your answer and you need to shake things up a bit to stand out. Good luck with the interview!