Don’t ruin the interview. Arrive on time. Dress well. Write a thank-you note. Don’t lie on the application. And–yup–don’t ruin the interview. You got the job-hunt basics down, but the demigods of employment have plagued your people with a drought. You need to know what not to do in an interview, so you don’t ruin said interview and all your hard work to land it.

Whether you’re interviewing after a layoff, seeking a change of employment or documenting your futile interviewing plight to milk yet another unemployment check, be aware of these five deadly interviewing sins of what you should never do in an interview.

What Not to Do in an Interview

1. Don’t get too friendly.

You can ruin an interview by toeing this line incorrectly. Imagine: You’re chatting with the interviewer, discussing professional experiences and swapping war stories; however, a relaxed interviewing environment is no excuse to become complacent in your professionalism.

An ex-colleague of mine was looking to migrate back towards web development, his original area of study and expertise. He was cordial, outgoing and a hard worker. He had plenty of experience and great references, but he met his downfall while making small talk. After the interview, the hiring manager mentioned in passing that he had recently received a DUI. My colleague, attempting to empathize, admitted that he, too, had received a DUI ticket. On three separate occasions. Lesson learned: get job first. Tell war stories later.

2. Don’t forget to train rigorously.

Reading job-seeking books, articles and studying potential interview questions are all great ways to prepare, but these resources don’t exactly put you in the interviewing hot seat. You wouldn’t expect to run a marathon just because you’ve read several books about running, would you? Get a friend or significant other to give you a dry run through a hypothetical interview with suggested questions from these books or articles. Even better, if you know someone who is a hiring manager or works in human resources (for a different company, of course), ask them to administer the mock interview.

By humbling yourself and asking for the help of others, you’ll receive constructive criticism and be able to integrate another perspective into your response. You may even be asked a question that you never considered answering, making great practice for unexpected interview surprises.

3. Don’t forget to shut up.

When you’re done answering the question, shut your mouth. The two deadliest kinds of interviewers we will refer to as the “poker face” and the “yes man.” The poker face will ask you a question and give no signs of life during the answer. In hopes of eliciting a smile, nod or comprehending grunt, you will elaborate. And elaborate. You will continue elaborating until you realize that the poker face is playing a game. By the time you realize you are involved in a game, you have already lost. Take this knowledge and answer the next question completely, concisely and without superfluous commentary.

The yes man is just as deadly, if not more so, than the poker face. He will nod his head and seem to understand and agree with every answer. Feeling encouraged by this enthusiasm, you will elaborate. And elaborate. You will continue elaborating until you realize that you could say your career goal’s to sleep with the boss, publish trade secrets and burn the building down, and the yes man would still nod his head.

In the yes man’s defense, sometimes he may actually agree with what you are saying at first, but, towards the end, every nod means “Yes, I understand. Just like I understood ten minutes ago. Please stop talking, lest I puncture my own eardrums with this letter opener.”

4. Don’t forget to tone it down.

Everyone knows not to bad-talk a previous employer, but even a comment where you feel you have restrained yourself may ring sour with the interviewer. If you’re jaded and bitter with your current job or the interviewing process, try to keep the disillusion to a minimum.

Take yourself to a happy place. Reminisce about the time you unwrapped a vending machine sandwich, locked it in your manager’s file cabinet and allowed their office to smell mysteriously foul for weeks. If your personality is sarcastic or dry, make sure to take this down a notch as well. While your friends and family may understand your charismatic quirks, a complete stranger may not.

5. Don’t forget to bring enough supplies to make a Boy Scout proud.

Bring a notepad, pen and three copies of your resume and references. Taking notes shows a proactive attitude and commitment to the interview. Additionally, these notes will be useful later when writing a personalized thank-you note to the interviewer.

If multiple members of management are administering the interview, make sure to provide a resume for each person. Worst-case scenario: you only bring one resume and end up with back-to-back interviews, thus leaving you empty-handed for the second round.

Bottom Line

Whether you’re rebounding from a layoff, looking for a different job or seeking excuses to stay unemployed, these tips will help you accomplish your objective. By becoming aware of these deadly interviewing sins, you’ve taken the first step towards meeting your goal!