1. Ask how much the position pays

Remember that you should never be the one initiating any money-related discussions, and certainly not before an offer has been made.  Some people ask this question before the interviewer has a chance to even ask the first question and this is a big mistake. It makes it seem as if all you are after is money. As a rule, wages and salaries are not discussed during the first interview. You may have three interviews altogether with one company. If money is discussed, it is up to the interviewer from the company to open up that subject. If they ask you how much money you want, have a range of salaries to give them and not a specific amount. First, research how much the job you want really pays in your town or state and then come up with a range of a yearly salary to request.

2. Ask what the company does

A job candidate must thoroughly research the company they will be interviewing with before going into a job interview.  A good place to start is their website as well as reading their press releases and other documents relevant documents.  

3. Use unprofessional language

Time and time again, interviewees perceive that an interview is going their way and decide to take the interview less seriously. This is especially true if the venue of the interview changes from a formal setting to a less formal setting such as a restaurant.  Unless you are drunk, maintain professionalism at all times you are in contact with the interviewers.

4. Criticize any former employers

Criticizing a former boss, not only shows a lack of professionalism, but also lets the interviewer know that you will do the same to them if you left their company. Instead, you can explain that you had a difference of opinion with your former employer in work philosophies or styles. Do not dwell on your answer about an employer where things did not go so well for you, and make it short.

5. Not ask any questions

Typically, interviewers will ask you if you have any questions for them toward the end of the interview. Never say no.  These questions actually present a good opportunity for you to show your interest in the company and also open further opportunities for additional discussions.  Thus said, you should stay away from questions whose responses can be found on the company’s website unless you are soliciting a clarification or offering a correction.