By Jessica Stillman,

Career advice is in no short supply. In fact, you could probably spend the duration of your working life simply reading through the tips and advice already online. But as in all areas of life, the more common something is, generally speaking, the lower its value.

Many oft repeated truisms are more about wish fulfillment than reality (sorry peddlers of endless, uncritical "follow your passion!" posts). Plus, tips that everyone and their mother (and their college career counselor) knows are unlikely to give you an edge over the competition. So what are the true hidden gems of career advice, the truths that few people are willing to say out loud that can actually transform a mediocre career into a rockstar one?

That's what a someone on question-and-answer site Quora wanted to know recently, asking: "What are a few unique pieces of career advice that nobody ever mentions?" The community responded with plenty of uncommon, thought-provoking advice.

Doing Your Job Well Is Not Enough

Being excellent at your job is a surefire way to get ahead, right? Nope, say several responders, including Victor Wong, CEO of PaperG. "Most people assume just doing their current assigned job well is enough--so many associates at law firms think doing all the paperwork and litigation properly is the road to partnership, and many PR account executives think that getting a few articles written about their clients will earn them a promotion," he writes, but "becoming a principal, partner, or senior executive with P&L-level responsibility requires a completely separate set of skills from entry and mid-level jobs."

How do you make that leap? "To make the big jump to the next level, they're really being benchmarked on their ability to deliver future value to the firm in ways that are not taught or explained to them: chiefly how much business are they are able to bring in," he asserts. "People who can think of what to do and deliver are the ones who ultimately are more likely to get promoted to the top levels."

Another anonymous poster agrees: "You don't become a star doing your job. You become a star making things happen."

Who You Work For Is Hugely Important

We all wish we lived in a world where who you know matters less than what you can do, but that's often not reality, and not always for unhealthy reasons. Knowing the best in the business often means you've worked with the best, and people rightly admire that.

"You don't have to be passionate about the product you are selling. You don't have to be in the most glamorous industry. You don't have to work for the company with the best 'brand' identity or reputation in your chosen field," insists Jeremy Boudinet, director of marketing for startup Ambition. What does matter is who you've worked with.

"Few things are as valuable as going and working for somebody that is going to want to teach you anything and everything they know. You'll experience tremendous personal and professional growth if you have the best person mentoring you," he says, so "figure out where the absolute best person to work for would be, and go work for them."

... So Is Where You Work

Just like who you work for can deeply affect the fate of your career, where you work also has a massive impact. Just saying, 'I want to work in software or sales,' isn't enough. Nor, as Boudinet point out, is it enough just to fill your resume with impressive company names. Your destiny is influenced greatly by the destiny of the particular organization that employs you. Don't take a job with just any old company because it's in the right sector or impresses your friends.

"Your career is a boat and it is at the mercy of tides. No matter how talented you are it's a lot harder to break out in a sluggish situation/hierarchy/economy than a go-go environment. Even if you're a superstar at Sluggish Co., your upside trajectory (more often than not) is fractional to what an average/below average employee achieves at Rocket Ship Co," says an anonymous poster with the most up-voted answer.

Being Seen as Super Busy Isn't Always a Good Thing

Think high achievers work endless hours and are continuously busy? Think again, writes Mira Zaslove, director of international sales and trading at FabExchange. "Ironically the busier you appear, often the less you will move up. I've seen smart and dedicated employees fail to get promoted, because they have taken on too much, are working too hard, and appeared too frazzled," she reports. "If you appear stressed, people will think you aren't prepared to take on more, and you'll miss opportunities for new and innovative projects."

Take a Tour

When plotting your first (or next) big career move, many of us think very abstractly, musing in solitude or in front of Google about the joys of our supposed dream jobs. But the truth is you can't decide on a career without seeing the day-to-day reality of where and how you work--the concrete truth rather than the imagined reality. Don't make decisions without actually going and seeing for yourself.

Alek Mirkovich, founder of campayn.com, once thought becoming an air traffic controller was a great idea, but then he took a tour of where he would actually be working. "Every single guy was BALD! Playing around with a simulator is fun but apparently the real thing is stressful. Within 30 seconds I knew I wasn't going to be signing up for this!" he remembers.

Don't Hide Your Failures

Failures are seen less as a signal of incompetence and more as a sign that you're willing to take a risk and innovate, according to Zaslove. "Your team will respect you and your career will accelerate if people understand what you are doing and that you are taking risks. Most people do not view someone as credible if they are giving advice and recommendations, but not walking the walk," she claims. "If you show that you are willing to take risks, and publicly falter, your team will feel confident taking risks too. Lead by example."

Execution Matters More Than Plans or Advice

Many people are looking for the magic recipe of how to make their career take off, but many of the responders agree that there are some serious limits to what other people can tell you. "Advice (like ideas) is not in short supply, there is plenty of it going around," writes coach Darren Beattie, for instance. "It's not really the advice in the long run that matters, it's the execution of the advice by the person being advised. The greatest advice ever in the history of the human race is absolutely useless if you act/execute on none of it."

Or to put it another way, there's no real roadmap that you can blindly follow. The trick is figuring out what to apply and what to ignore for your own personal situation. That same popular anonymous responder sums this idea up well: "Career tracks and meritocracies don't exist: Your career is not a linear, clearly defined trajectory."