15 Career Mistakes to Avoid in 2015

Banish these blunders.

Sometimes the best way to start doing something right is to stop doing something wrong. Career-wise, this particularly rings true. Witness a professional sea change after you remove these 15 mistakes from your repertoire.

Applying for any and every job.

Unemployment can feel desperate, but you must still be conservative during a job search. Don't submit job applications and résumés for postings for which you're not qualified, says Dan Schawbel, career expert and author of "Promote Yourself: The New Rules for Career Success." For one, "You won't have any positive results, because employers are looking for a perfect match." And on the off-chance you do get the job, you might find yourself overwhelmed to fill a role for which you're ill-suited.

Having a flimsy social-media presence.

If you can't be found online at all -- or if Googling your name leads a recruiter or employer down a NSFW rabbit hole -- you're sending the wrong message. Safeguard your Twitter feed and Facebook timeline. "Before you post a comment online, think: Is it stupid, thoughtless and insensitive? How will this affect my company? How could this be interpreted by someone who doesn't know me?" says Andrea Kay, an author, career consultant, syndicated columnist and speaker. "And remember that anything you write -- emails included -- can be easily forwarded and read by someone you may not have intended to read them."

Ignoring your LinkedIn account.

Revive your rusty LinkedIn account, not to mention your rusty career. This isn't just a useful website when you're job searching. LinkedIn is also critical for documenting your accomplishments, networking with current and prospective business contacts and staying up to speed on industry trends.

Being a team of one.

Remember that career success is communal. Are you switching careers? Tell your friends and family. Are you seeking continued education opportunities? Speak with your colleagues about previous courses they've taken. Are you struggling with how to handle a particular workplace challenge? Consult with a mentor. Relying solely on who and what you know could lead to unnecessary setbacks (plus it's lonely).

Not keeping up with the latest news and trends.

Staying out of the loop about your career and industry will keep you out of the running for good job opportunities and raises. And you'll appear uninformed during interviews (which is appropriate, because you are uninformed).

Being passive about your worth.

Attempting to negotiate a higher salary upon receiving a job offer doesn't make you disagreeable. And if you're currently employed and generating consistently stellar work, it's understandable that you'd request a pay bump.

Being the office pariah.

It's a bad idea to skip every office happy hour and out-of-the-office lunch. These events are where you'll earn the most personal capital, and who knows when you might need a professional ally? Do exercise restraint, though -- being the office gossiper isn't a good look, either.

Quitting your job search once employed.

Never rest on steady-paycheck laurels and then fail to network, keep your résumé updated, or stay tuned into employment trends and job opportunities in your field. You don't want to be caught unprepared for a sudden change of fortune.

Complaining too much.

Subpar salary, sour supervisor, sucky schedule. All are valid reasons to be bummed about your place of employment. Just be mindful of how quickly healthy venting turns into incessant complaining. Neither your professional nor personal circle will want to hear too much of your griping. If you're miserable at your job, make moves to find a new one.

Working while sick.

You're not a professional martyr if you come into the office sick, you're just Patient Zero of the office plague. Take the necessary time to recuperate at home; doing so will prevent you from spreading germs, and it could also keep you from making some cataclysmic, cold-medicine induced, career-damaging mistake.

Failing to continue learning.

Your degrees and/or on-the-job training will only take you so far. Any job's relevant skills are fluid, and it's easier to be constantly learning than to have to play catch-up.

Being a clock-watcher.

While you're at work, be at work. And put in a full day's work at that. "If you arrive in the nick of time in the morning and pack up five minutes early in the afternoon ... you are sending the message that you are just going through the motions," says national etiquette expert Diane Gottsman, owner of The Protocol School of Texas. "Making a positive impression, being seen as a team player and showing your boss (and fellow colleagues) you are invested in the company requires you to arrive early enough to make your first cup of coffee before the day begins and finish a project that is time-sensitive, regardless of what the clock says."

Being one with your smartphone.

We know this one is a toughie. But consider limiting the texting, Instagramming and personal calls while you're on the clock. Gottsman suggests turning your phone off altogether. "Nothing will kill the deal for you at a job interview, in a meeting or with a client, like a cellphone making a vibrating noise in your pocket, briefcase or purse," she says. "It sends the message that you either lack executive leadership skills by forgetting to turn your cell off or that you are waiting for a call that is more important than the meeting you are currently in."

Expecting your manager to manage your career.

Don't wait on a busy boss to buoy you up every rung of the corporate ladder. Toot your own horn from time to time. Provide your own evidence for why you should have a raise. Do your own research to enroll in courses to learn new skills. "Companies care about making a profit, not about your career. So it's your responsibility to take charge," Schawbel says.

Ignoring your company's overall mission.

Lend a hand during important office initiatives. Offer encouragement or feedback when your colleagues are working hard on a project. Make suggestions on how to improve business as a whole, not just in your department. Being a dependable colleague will make you a greater asset to your team and could ensure your longevity in your position.

Jada A. Graves is the Careers product manager at U.S. News. You can follow her on Twitter @jadaagraves, circle her on Google+ or email her at jgraves@usnews.com.