If you're having trouble finding a job, it might be because you're sabotaging your chances without even realizing it.

Here are 10 common mistakes that you're possibly making in your job search:

1. Relying on outdated sources of job-searching advice. Job-search conventions have changed dramatically in the last 10 years, but many books and experts are still doling out outdated advice that can hurt your chances now. Ideally your advice should come from sources who have done a significant amount of hiring themselves—and recently, not a couple of decades ago.

2. Mainly listing job duties on your resume, rather than accomplishments. Job descriptions don't belong on your resume; accomplishments do. Resumes that stand out go beyond what duties you were responsible for and instead answer this question: What did you accomplish in this job that someone else might not have?

3. Feeling that your resume must be a complete account of everything you've ever done.Your resume is a marketing document intended to present you, your skills, and your experience in the strongest light. You're not required to include that short-term job from which you were fired, or the one outside your field, or your year in law school before you flunked out.

4. Sending your resume without a cover letter. If you're applying for jobs without including a compelling cover letter—customized to this specific opportunity—you're missing out on one of the most effective ways to grab an employer's attention. A cover letter is your opportunity to make a compelling case for yourself as a candidate, totally aside from what's in your resume. You're doing yourself a disservice if you don't include one.

5. Annoying employers with too much follow-up. Job-seekers are sometimes advised that they should call employers to check on their application or to try to schedule an interview. But most employers don't respond well to this, viewing it as overly aggressive and annoying. After all, you're not the only person applying for the job; multiply your phone call by 300 applicants, and you'll see why employers are annoyed.

6. Not preparing for interviews. If you're not preparing for interviews by practicing your answers to likely questions, and by providing examples from your past work that clearly demonstrate why you'd excel at the job, you're probably selling yourself short. Few people interview well on the fly; if you don't prepare in advance, you're likely to be passed over even for jobs for which you're perfect.

7. Not understanding how to "stand out" as a candidate. Job-seekers often think they need to find a creative way to stand out from the sea of other candidates, so they try fancy resume designs, video resumes, sending the hiring manager cookies (yes, really), and other gimmicks. But gimmicks don't make up for a lack of qualifications, and they'll turn off many hiring managers. This isn't what many job seekers want to hear, but the way to stand out is by being a highly qualified candidate with a track record of success in the area for which the employer is hiring, by writing a great cover letter, and by being responsive, thoughtful, and enthusiastic.

8. Not paying attention to your references. When you're asked for references, you don't want to have to scramble to track down that manager from six years ago, or that boss who has since retired. Instead, make sure that you stay in touch with the people you'll want to use as references some day, so that you don't have to hunt them down—or remind them of who you are—when that reference check comes around.

9. Ignoring danger signs. When you really want a job, it's all too easy to ignore signals that a company might turn into the workplace of your nightmares. But if you don't want to end up in a job that regularly leaves you in tears, it's important to pay attention to red flags, like flakiness, high turnover, or a manager who seems like a jerk.

10. Becoming bitter. Job searching is frustrating, especially in this market, but if you let unemployment make you bitter, you'll probably turn off potential employers. It's nearly impossible to hide bitterness if you feel it, so it's crucial to find ways to have a more positive outlook.

Read more at: http://money.usnews.com/money/blogs/outside-voices-careers/2012/05/02/10-costly-job-search-mistakes-you-have-to-stop-making