I would spend some time researching the recruitment process and how best you will tackle it. A good idea would be to start a word document and take a note of things you do in your life that could be used to demonstrate a certain "competency" that an airline looks for e.g teamwork. This is the general way of recruitment and it is possible to improve greatly at these interviews. I don't think they are a good thing at all but unfortunately often stands in the way between you and the job you want.
Good luck!