Be a problem solver
Positions are created because the company wants to solve problems such as ineffective ad campaigns or long customer service lines. Here you have to first identify the problems hinted in the job ad. If there is no job ad, know the company and the industry and find out the problems being faced. Then prepare solutions for the problems with examples and be ready to tell the interviewer how you had solved similar problems. Practice telling stories about your problem solving achievements.
Are you seeking a career change? Understand problems such as lack of effective project management or faulty team work are not just industry specific. Offering solutions to such problems gives you an opportunity to underscore your ability to do well even if you don't have direct applicable experience.
Be specific
Avoid clichés. Substantiate your claims about your skills or characteristics with relevant stories. For instance just don't say that you can work well with your team, but tell the interviewer about the types of teams you have worked with and narrate your learning experiences. Or if you want to say you have an eye for details, prepare a story about how you have saved money or time for your employer with your attention to details.
Effective sound bites
Prepare three or four effective sound bites about your accomplishments. Mind you, sound bites are effective, catchy and easy to remember. Say: "I've designed logos for three Fortune 500 companies" or "My plan worked out well and reduced the product delivery time by about 15 % without any additional expenditure to my present employer."
When you are preparing your sound bites only think about your recent achievements that make you stand out in a crowd of candidates.
Your resume
Your resume and the cover letter open up an opportunity to talk about your experience and accomplishment. A resume should be brief with many points that can be explained in detail in the interview. The resume may say about what you have done. Use this point to tell the interviewer how you have achieved it with your skill and ability; how you gained the skills. You can speak elaborately about the praise you have received from your employer for a particular achievement.
Non-verbal communication
Your body language speaks a lot about you. The way you are sitting in the chair, your facial expressions and gestures reflect your attitudes. Sitting up straight indicates you are closed off. Respond to questions looking straight into the eyes of the interviewer. Keep a smile. Give a firm and confident handshake; an aggressive handshake or a limp one spoils your chances. Practice handshake with a friend.
Be positive
Don't complain against a former employer or blame a former manager. If you do so, the interviewer thinks that you are a difficult person to deal with or you are disloyal. Even if you have quit a job in a huff because of your incompetent manager, say something like this: "I think I should opt for a more challenging job like this." With such a positive response you may able to turn the interview to your advantage.