All it takes is three seconds, according to one expert, to find work at a job fair.

You can also ruin your chances in that same tiny amount of time.

Three seconds?

"You need to be able to go up to somebody, shake their hand, and in the three seconds, you have to make a good first impression," says Mike McNamara with Talent Boulevard. "That's how you crush it."

McNamara's been on both sides of the equation at job fairs.

"I've been there as a candidate and I've been there as an interviewer," McNamara said. "And being a candidate is much more fun than interviewing. So, it's about going there having fun and being able to tell your story."

Having a 'story' that presents your best qualities, either in a previous job or other experience, can be the clincher at a crowded, and competitive, job fair.

"It's all about telling that story, telling your situation and what kind of action you took as a result of that," McNamara said. "You become a good short storyteller, and that's who wins at a job fair."

A job recruiter will look at your resume for an average of 17 seconds, McNamara says. Make sure you punch it up with dynamic, active verbs and phrases.

Some other useful nuggets:

Make good contact, if that's something you struggle with, focus on the other person's nose.

Limit your smart phone activity as much as possible, bring a legal pad, if you need, to take notes and appear eager.

Crossing your arms is a bad look.

And when you're at a job fair, by all means, do not walk around with earbuds or headphones on.

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