During the interview, the hiring manager is trying to get a sense of who you are — you can answer all of their questions perfectly, but what about everything else you do during the time that you spend together? Are you supposed to accept the cup of coffee they offer? And what do your hand movements say to them? And who are you supposed to look at in a panel interview? In the book "Crazy Good Interviewing: How Acting A Little Crazy Can Get You The Job," John B. Molidor and Barbara Parus say jobseekers need to take into account that their interviewer may very well be from a different generation or have a different personality than the candidate, so use this scenario to your advantage. "A common complaint among many interviewers, especially older ones, hiring agents, and human resources professionals today is that younger job applicants — namely, those who fall under the Generation X and Generation Y labels — arrive completely unprepared or, worst yet, have a large sense of entitlement."

Here are some things you didn't know about the interview, but, in a competitive job market, you probably should.

If they offer you something to drink besides water — especially coffee — don't accept it.

Your interviewer doesn't want to spend 10-minutes just to make you a cup of coffee. And if they have a busy day ahead, it will just annoy them that they're spending even more time than they originally planned. Furthermore, if you needed coffee, you should've had it before coming to the interview.  "If you are offered coffee, politely refuse. It could spill and create a distraction during the interview. Coffee relaxes the sphincter and you might need to make a mad dash for the restroom."

Don't sit until you're told to do so.

"Do not sit down until you are offered a chair. Then, sit tall with squared up shoulders and try to occupy as much space in the chair as possible. Don't be like a shrinking violet with a bowed head, no eye contact, and slouching shoulders."

"By leaving a timid impression, a potential employer will not feel confident about hiring you to tackle assignments that require some chutzpah."

Guess the age of your interviewer, and alter your answers depending on this

Different generations are most impressed by different values, so by being aware that your interviewer is from a different generation than yourself, you can adhere to what you think they want in an employee. "With little practice, you can hone in on the values that each generation holds most dear. You can shape your answer using the language of their values."

Keep everyone's attention in a panel interview by making eye contact with different people at specific times during your response.

In a panel interview, always begin your response by making eye contact with the person who asked you the questions. Then make random and soft eye contact with each of the other interviewers."

"As you finish up your response, return your eye contact to the person who asked you the question. Do not mow down the interviewers by going down the line making eye contact after the other. Soft random eye contact does the trick."

If your interviewer is playing head games with you, don't reveal that you know what's going on.

You should leave the head games to them, and don't let it affect your own strategy.

"If you have the sneaking suspicion the interviewer is jerking your chain, you are probably right. Unfortunately, some interviewers will play mind games with job candidates to test their reactions. If they are unflappable, you will pass the acid test and may receive a job offer or, at least, be a finalist. If you crumble, then the interviewer will assume you probably cannot handle the stresses of the job."

If you're unsure, always wear light-colored clothing

You should, of course, always dress your best for an interview. If you're unsure of the work culture, go with light-colored clothing.

"A crisp, white, long-sleeved shirt is your safest option, even in summer. You can also wear a long-sleeved shirt in a solid light blue, cream, or almond. Dark shirts are too trendy for conservative industries, such as banking and accounting, and are reminiscent of the tough guys in The Sopranos, The Godfather or Goodfellas."

Know the messages your hands are saying:

Showing your palms indicates sincerity.

Holding your palms downward is a sign of dominance. Do not shake hands with your palms down

Pressing the fingertips of your hands together to form a church steeple is a display of confidence.

Concealing your hands, as in putting them in your pockets, is a sign that you have something to hide.

Finger tapping is a sign of impatience.

Folding your arms across your chest is a very defensive position, indicating disappointment or disagreement.

Overusing hand gestures to the point of distraction.

Know the messages your head and shoulders are saying:

Touching your ear or scratching your chin is a sign that you don't buy the bull.

Tilting your head forward is a sign of shyness.

Tilting your head backward shows overconfidence or pride.

Tilting your head to one side could be construed as boredom.

Tilting your head slightly to the side shows you are friendly and ready to listen.

Glazed eyes staring straight ahead indicates boredom (or a hangover).

Excessive blinking is a sign of lying.

A harsh or blank expression indicates hostility.

Shrugging your shoulders could be viewed as willingness to unload a problem or burden, or a sign of impatience or total detachment.

Decide whether your interviewer is an extrovert or an introvert and alter your body language depending on this.

This is because if you have the opposite personality as your interviewer, you can easily "get on each other's nerves and will get in each other's way."

"With an extrovert interviewer, the job candidate should be talkative and animated," whereas "with an introverted interviewer, the interviewee should reflect on the question in silence, and then respond."

If you don't do this, the interviewer may determine your actions are communicating something that you don't intend them to. For example, if you're an introvert and prefer to think about your answers before speaking, the interviewer may take your silences as "troubling."

Showed interest by leaning toward you.

Put phone calls on hold.

Smiled occasionally and nodded his or head head in agreement.

Exhibited some mirroring techniques.

Inquired when you could start working.

Called your references right after interview.

Talked up the benefits of the job and working for the company.

You'll know you bombed the interview if:

Your interview was cut short.

The interviewer started shuffling paperwork or answering their phone while you were speaking.

There was no discussion about the next steps or salary requirements.

You were invited back for a second interview, but no one showed you around the office or introduced you to other employees.