Great interviews arise from careful groundwork. You can ace your next interview if you:

Act spontaneous, but be well prepared. Be your authentic self, professional yet real. Engage in true conversation with your interviewer, resting on the preparation you did prior to coming to the meeting. Conduct several trial runs with another person simulating the interview before it actually occurs. It's the same as anticipating the questions you'll be asked on a final exam. 

Set goals for the interview. It is your job to leave the meeting feeling secure that the interviewer knows as much as he or she possibly can about your skills, abilities, experience and achievements. If you sense there are misconceptions, clear them up before leaving. If the interviewer doesn't get around to asking you important questions, pose them yourself (diplomatically) and answer them. Don't leave the meeting without getting your own questions answered so that you have a clear idea of what you would be getting yourself into. If possible, try to get further interviews, especially with other key players. 

Know the question behind the question. Ultimately, every question boils down to, "Why should we hire you?" Be sure you answer that completely. If there is a question about your meeting deadlines, consider whether the interviewer is probing delicately about your personal life, careful not to ask you whether your family responsibilities will interfere with your work. Find away to address fears if you sense they are present. 

Follow up with an effective "thank you" letter. Don't write this letter lightly. It is another opportunity to market yourself. Find some areas discussed in the meeting and expand upon them in your letter. Writing a letter after a meeting is a very minimum. Standing out among the other candidates will occur if you thoughtfully consider this follow up letter as an additional interview in which you get to do all the talking. Propose useful ideas that demonstrate your added value to the team. 

Consider the interviewer's agenda. Much is on the shoulders of the interviewer. He or she has the responsibility of hiring the right candidate. Your ability to do the job will need to be justified. "Are there additional pluses here?" "Will this person fit the culture of this organization?" These as well as other questions will be heavily on the interviewer's mind. Find ways to demonstrate your qualities above and beyond just doing the job. 

Expect to answer the question, "Tell me about yourself." This is a pet question of prepared and even unprepared interviewers. Everything you include should answer the question, "Why should we hire you?" Carefully prepare your answer to include examples of achievements from your work life that closely match the elements of the job before you. Obviously, you'll want to know as much about the job description as you can before you respond to the question. 

Be smart about money questions. Don't fall into the trap of telling the interviewer your financial expectations. You may be asking for too little or too much money and in each case ruin your chances of being offered the job. Instead, ask what salary range the job falls in. Attempt to postpone a money discussion until you have a better understanding of the scope of responsibilities of the job. 

Don't hang out your dirty laundry. Be careful not to bare your soul and tell tales that are inappropriate or beyond the scope of the interview. State your previous experience in the most positive terms. Even if you disagreed with a former employer, express your enthusiasm for earlier situations as much as you can. Whenever you speak negatively about another person or situation in which you were directly involved, you run the risk (early in the relationship) of appearing like a troubled person who may have difficulty working with others.