The next is after knowing your facts, know the job. Although you may think that you know all about the job you have applied for, don't let that stop you from learning more about it. An interviewer is going to ask you why you want the job and at that point you may stuck. So don't let that happen. Next I'd say is be confident but not cocky. Now, it may seem hard to do this, but you need to get the balance right now