You are confident and feel you will be able to present yourself well and provide needed or excellent answers to important questions in order to pass your interview. However, remember that knowing what to say and do is as important as knowing the things that you should avoid to say or actions you should be careful not to show.

So here's one last reminder before going to that interview. Here are things that you should keep mum about and other things to avoid so you don't create a bad impression.

Do not say bad things about former employers. Even if it is true that you hated your last job and everything about it (e.g. the boss, the organizations, work ethics of former officemates) it is not proper to vent out how much you dislike them during an interview. If there is really hardly any nice things you can say about the job and the boss, it creates an impression that you are a whiner and if ever hired will also say bad stuff about the company that you've worked for to others.

However do not lie either and say that you love your former job or boss when you really don't. If you had bad experience with a former job, explain why the work organization and management was not right for you and mention what kind of job and boss you think you will be able to work best.

Do not display ignorance. One of the most common questions asked during an interview is if your knowledge about the job and the company you are applying for. The interviewer would expect you to at least have an idea, so saying that you know nothing about the company would turn off most interviewers. So doing some research to prepare your answers to this question will pay off.

Do not display lack of interest. Towards the end of the interview, the interviewer is likely to ask if you have any questions for him/her. This is your chance to inquire some things about the company and the job so don't waste it by saying you don't have any questions. This will show that you are not interested with the job and probably will not be an efficient employee.

Do not ask for a leave or day off right away. Employers are humans too so they understand that workers need to have a time off from work so day off and paid vacation leaves are common benefits enjoyed by a regular worker. However discussing your need for day offs and vacation leaves is not discussed during an interview. In fact that should be the farthest thing from your mind if you are seriously looking for a full time job.

Do not be too demanding. Saying that you want to earn this much in less than a year of work or expect to get a promotion fast would signal that you are a goal-oriented and ambitious person and may probably be a good sign at some point but not during an interview. Instead of saying what you expect to get from working in the company, specify first how the company can benefit from hiring you.

Do not cross boundaries. Some interviewers make an effort to make the applicant feel at home and relaxed by sounding less formal and asking a bit of light personal questions. If this happens, be grateful for the thoughtfulness but don't forget to remain formal and civil still. Avoid crossing the boundaries by asking very personal questions or sharing very personal information about you that is in no way related to the job.

Do not sound so rehearsed. Yes you have prepared and anticipated possible answers but do not make your answers sounds like you are just delivering a script.

Source: http://www.jobopenings.ph/article_item78/What_Not_To_Say_In_An_Interview.html