If you are one of the lucky ones who get to the interview stage, then you want to make sure you are FULLY prepared. Preparation for an interview should take longer than any other part of the process. and it should be done carefully so you are able to gather as much information as possible to give you the best chance of presenting the best picture of yourself to the interviewer.
If you practice and gain an understanding of all areas of the interview process you have a better chance of being successful. Try practising with someone else asking you questions a few times. Remember that it's always worse in your head, fake confidence and remember to breathe. Think it through beforehand and know exactly what you want to say.
There's nothing worse than leaving an interview with the thoughts and feelings of "I wish I had..."
If you are unsuccessful, but you did your best, then that is still good experience. You can learn from it and carry those skills forward.
Now you have all the skills you need to ace your job interview. Remember to be yourself, and let them know how enthusiastic you are.