Referred by a friend. I was told initially it was more likely I would get invited for an interview if I knew somebody that worked for shell and included their name in the application. The initial application process was straightforward to be honest.
The interview on the other hand was a different story. It was a competency based one, with three questions. I barely remember all the questions, but I will give it a try.
I cannot really advice on how to do well however, my advice is to be yourself and TAKE your time before you answer any of the questions. The interviewer was very professional and pleasant and I can only blame myself for lack of preparation before attending the interview session.
Good luck