The key to a successful interview is to stand out in the employers mind. This doesn't mean wear funky clothes. To stand out, you need to stand for something. Pick one or two things you want the employer to remember about you. Refer to those one to two points several times during the interview.
For example, you may choose to brand yourself as someone who is deadline driven. When asked about working in a team environment, answer the interview question but feel free to weave in your main point. "Because I am so deadline driven myself, I’ve really learned how to work with others’ strengths and weaknesses in order to reach our goals on time.”
Vague responses will almost guarantee you a rejection letter. Not only are vague responses easily forgotten, they carry little credibility. By providing detail to each interview question, your answers become more real, tangible and most importantly... memorable.
Mistakes #1 and #2 are usually caused by lack of preparation. Give yourself plenty of time preparing answers to the interview questions related to the position you are applying for. Make sure you have a firm grasp of the products or services sold, the customers the company serves, and the competition. There really is no substitute for preparation.