That really depends on the business unit and what level Graduate is a long process of interviews, group activities and case based evaluation.
Treat it all professionally and trust yourself.
Experienced hires could be anything from one interview or many case based or not. Sell yourself at every opportunity.
It depends on which level and business unit you are trying to move into. A graduate has to go through the program - the best thing I could say is be yourself if you don't match PwC criteria you DON'T want to be there.
Experienced - personality and experience take a sales based approach to your career detail how much benefit you have provided to the company or companies you worked for (putting it terms of money gained or saved is helpful).
How you manage your personal network, this can be more important than experience even if you aren't going into a sales role.
Soft skills - client, people management, it doesn't matter how or in what capacity retail sales project management etc.