Finding a job still isn't all that easy for many workers in the post-recession years, but some may be unknowingly sabotaging their own chances of getting a job offer.

First impressions are hugely important, given that half of all hiring managers said they know within the first five minutes of an interview whether a candidate will be a good fit, according to a new survey from career site CareerBuilder. The study, conducted by Harris Poll, surveyed more than 2,500 hiring and human resource managers late last year.

It takes more than a sterling resume to get hired, given that body language and strange habits can derail a candidate's chances. It turns out there are several sure-fire ways to ruin a job interview. Hint: if you are tempted to answer a cellphone or text during the interview, take a deep breath and put the mobile phone down. No one likes to have their conversations interrupted by texting or calls, and that certainly holds true for hiring managers, with 68 percent saying it's a deal breaker.

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"Candidates have to make a great first impression appearance-wise, have a solid understanding of the target company, know exactly how to convey that they're the perfect fit for the job and control their body language," said Rosemary Haefner, CareerBuilder's chief human resources officer.

Other faux pas that can sink a candidate's chance of getting an offer include lying about something, appearing arrogant or entitled, and dressing inappropriately. Candidates with salty language should tone down their vocabulary, given that half of hiring managers say that's an instant sign that someone isn't a good fit.

Then there are the body-language issues. If you have a weak handshake, use too many hand gestures, or forget to smile, you may be headed back to the job search, the survey found. The biggest body-language turn-off? Failing to make eye contact, with more than two-thirds of hiring managers saying it's a mistake that weakens a candidate's chances.

Then there are the truly odd behaviors that hiring managers report encountering, such as one candidate who applied lotion to their feet during the interview. Another sang her responses to the interview questions, while a third carried their pet bird in their pocket to the meeting.

Phone interviews are also subject to weird behaviors, the study found, given that one candidate carried on the conversation while in the bathroom and flushed, tipping off the hiring manager about the interviewee's location.

Aside for giving yourself a reality-check about your handshake or eye contact, CareerBuilder recommends spending some time interviewing yourself for the job. That means asking a friend or colleague to pose mock questions such as, "Why are you a good fit for the job?" and then practicing your response.

The two most common questions that hiring managers report asking are: "Tell me about yourself" and "Why do you want this job?"

It's also important to stay positive and avoid trashing your prior employers or bosses, CareerBuilder notes.