Acing an interview is an important step in landing a job, but it's no easy feat, and your time to show yourself off is limited. According to a new CareerBuilder survey conducted by The Harris Poll, around half of employers (49 percent) know within the first five minutes of an interview if a candidate is a good or bad fit for a position, and only 8 percent make up their mind within a half hour or longer.

This survey was conducted online by The Harris Poll from November 28 to December 20, 2017 and included a representative sample of 1,014 hiring managers and human resource professionals across industries and company sizes (of which, 888 are in the U.S. private sector).

"There's a lot riding on an interview — you have to make a great first impression, have knowledge of your target company and its product, and know exactly how to convey that you're the perfect fit for the job," said Rosemary Haefner, chief human resources officer at CareerBuilder. "The best thing you can do for yourself is to prepare and practice everything from your body language to answers to standard interview questions. You never get a second chance to make a first impression, so going in well-prepared is key."

The Most Unusual Things People Have Done in Job Interviews
When you're not prepared, crazy things can happen. When asked to share the most unusual things job candidates have done during the interview process, employers and hiring managers recalled the following:

• Candidate did not have the skills to do the job and stated, "Fake it until you make it" as his personal philosophy.

• Candidate asked interviewer if she was qualified to be doing her job.

• Candidate asked for a cocktail.

• Candidate asked to taste the interviewer's coffee.

• Candidate called a government job "something government-y."

• Candidate came to interview wearing slippers.

• Candidate wore a Darth Vader outfit to the interview.

• Candidate spent a lot of time quoting Dwight D. Eisenhower, which had nothing to do with the position he was interviewing for.

• Candidate leaned far forward with his head down during the first five minutes of the interview.

• Candidate offered interviewer pumpkins and said they transfer good energy.

• Candidate pulled out a bag of drugs with his keys.

• Candidate broke out in song in the middle of the interview.

10 Mistakes That Will Instantly Destroy Your Chances
Even if you are the best candidate for the job, you can see a potential offer go up in smoke by making avoidable mistakes. Here are 10 instant deal breakers, according to employers:

1. Candidate is caught lying about something: 71 percent

2. Candidate answers a cell phone or texts during the interview: 67 percent

3. Candidate appears arrogant or entitled: 59 percent

4. Candidate appears to have a lack of accountability: 52 percent

5. Candidate swears: 51 percent

6. Candidate dresses inappropriately: 50 percent

7. Candidate talks negatively about current or previous employers: 48 percent

8. Candidate knows nothing about the job or company: 45 percent

9. Candidate has unprofessional body language: 43 percent

10. Candidate knows nothing about the industry or competitors: 35 percent

The Importance of Body Language
Sometimes your body language communicates more to another person than what you say or the tone of your voice. When asked to identify the biggest body language mistakes job seekers make during an interview, hiring managers named the following:

1. Failure to make eye contact: 68 percent

2. Failure to smile: 38 percent

3. Playing with something on the table: 36 percent

4. Fidgeting too much in his/her seat: 32 percent

5. Bad posture: 31 percent

6. Crossing their arms over their chest: 31 percent

7. Playing with hair or touching one's face: 26 percent

8. Handshake that is too weak: 22 percent

9. Using too many hand gestures: 13 percent

10. Handshake is too strong: 8 percent