FORTUNE — Dear Annie: I’m a latecomer to Twitter, having finally gotten around to opening an account a few months ago. So far, I’ve really only used it to keep up with friends and follow a few sports teams and the like. But now I’m looking for a new job, and I’ve heard that Twitter is a great job-hunting tool, but I’m not sure how to use it that way. Should I give it a try, or focus my job hunt on LinkedIn and in-person networking instead? What do you and your readers think? — Just Joe
Dear J.J.: Employers from AT&T (T) to Zappos, as well as many recruiters, routinely troll Twitter in search of job candidates, and it can be a valuable source of informal leads. “People often put out the word about openings that aren’t advertised anywhere by tweeting something like, ‘A friend of mine is looking for a new creative director — know anyone good?’” notes Thomas Gimbel, CEO of Chicago-based recruiting and staffing firm LaSalle Network. “Twitter is a great tool for hearing through the grapevine who’s hiring, and for communicating quickly with potential employers.”
That said, he adds, “Lots of people are looking for one quick, surefire path to a new job, and Twitter is not that. It works best when you use it to build relationships, which takes time. Not only that, but how you present yourself on Twitter can help or hurt your job search, so you need to be careful how you use it.” Consider the following six suggestions:
1. Try a shortcut or two. Sites like TweetMyJobs, TwitJobSearch, and Jobshouts offer to act as go-betweens, scouring Twitter to find mentions of job openings with keywords you choose, then tweeting you the information; or else they work directly with companies that have jobs to fill. It might be worth your while to check out one or more of these outfits. TweetMyJobs, for example, says Prudential (PRU), UPS (ups), GEICO, Tenneco, AstraZeneca (azn),and many others are currently signed up to find candidates through its service.
2. Get your Twitter profile in shape. Since it’s increasingly likely that a prospective employer will look you up on Twitter as well as on LinkedIn (lnkd), make sure your profile (limited to 160 words) explains what you do, where you do it, and what kinds of opportunities you’re interested in. Don’t forget to include keywords that hiring managers and recruiters might use when searching.
3. Follow a carefully chosen few. Once you’ve figured out which companies you’d most like to work for, follow them, as well as hiring managers (who often post their Twitter profile URLs on LinkedIn). “One good thing about Twitter is that you can connect with anyone you want, without having to ask them first,” Gimbel says. “On the other hand, to keep from being swamped in a sea of irrelevant tweets, don’t follow 100 companies or individuals. Be selective and limit yourself to a couple of dozen at the very most.”
4. Practice the art of the strategic retweet. “Imitation really is the sincerest form of flattery, and retweeting something is a compliment,” notes Gimbel. “People notice who retweeted what, and they’ll often look up that person’s Twitter profile. That doesn’t mean they’ll hire you, but it gets you on their radar.”
Like any other form of flattery, retweeting works best when used sparingly. “Don’t do it just to get on someone’s good side, or retweet every single thing they send out,” Gimbel advises. Instead, pick just the Tweets with some genuine substance, and add your own brief (and, ideally, knowledgeable and interesting) comment.
5. Have a 140-character “elevator pitch” handy. Let’s suppose someone you want to know better Tweets at you to say, for instance, “Thanks for the retweet.” How do you respond? “You can’t tell your whole life story in 140 characters, but you do need a concise bio ready to go,” Gimbel says. “It should simply tell the essence of who you are, professionally, as briefly as possible. You may not even have to use all 140 characters. If you can do it in 90 or 110, even better.”
6. Assume a recruiter or employer will see everything you tweet. Observing that most people make an extra effort to look and dress their best during a job hunt, “because you never know who you might run into on the street,” Gimbel notes the same principle applies to Twitter. “For the duration of your job search, avoid tweeting anything too personal. Err on the side of presenting a very professional persona,” he says. Your friends may miss some of your juicier commentary, but they’ll understand.
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And speaking of the Tweets you send, be sure to proofread them first. That may sound obvious, but apparently it isn’t. “I had a job candidate Tweet me recently and spell his own name wrong. He typed Tim instead of Tom and then hit ‘send,’” Gimbel says. “That tells me he lacks attention to detail. He’s moving too fast to get even the simplest things right — not exactly what an employer wants to see.” Enough said.
Talkback: Has Twitter ever helped you find a job? If you’re a hiring manager, how important is Twitter in your perception of a candidate? Leave a comment below.