By Bernard Marr,

It’s easier than you might think to ruin your entire career with one super stupid move. A PR professional ruined her career with one thoughtless tweet. Many careers were ruined by supposedly private emails leaked at Sony. A police officer in Atlanta was fired for sharing sensitive information about his job — like the hours he would be working as a plainclothes officer — on his private Facebook page.

Of course, these sorts of gaffes aren’t new — it’s just the way they’re happening (digitally) that’s different. People have been making stupid mistakes that can ruin their careers for hundreds of years, but it’s gotten much easier since the advent of social media.

How can you avoid these classic blunders in the digital age? Here, I list 5 really dumb ways to ruin your career in the hopes that thinking about them will make you less likely to do them.

1. Forgetting that everything — and everyone — is connected.
I mean this in two senses. First, think about the idea of six degrees of separation: that you are connected to everyone else on this planet within six people. (LinkedIn is founded on a very similar belief.) In a particular field of business, it’s even smaller. So doing a foolish thing like quitting a job without giving notice, making enemies, or treating clients badly will follow you. You never know who at your old company knows the boss at the new company you’d like to work at, so try not to alienate anyone.

In the second sense, I mean that everyone is connected to the Internet. Those photos of you doing embarrassing things on the weekends or on vacation? There’s no privacy setting strong enough. And those comments you made about your boss or clients on Twitter? Consider that grounds for dismissal.

2. Bringing too much personal life to your work life.
This can take any number of forms. Most employers have accepted that employees will be occasionally checking their phones or looking at Facebookduring the workday (even if they don’t like it), but spending a disproportionate amount of time at work on non-work phone calls or social media sites is a quick way to get on the boss’ bad side. Likewise, if drama outside of work is constantly making you late, miss work, or unable to focus, you won’t be seen as an asset, but a liability. Too many excuses, even if they’re legitimate, will add up to you being seen as unreliable. Try to keep work and home life as separate as possible. If you are having severe problems, like a sick family member, talk to your manager or HR as soon as possible so that they understand the situation. One or two bad days won’t ruin your career; a string of bad weeks or months might.

3. Lying.
It may seem not lying should go without saying, but lots of people tell little white lies at work, and those fibs can grow and morph into big hairy audacious lies. It might start with inflating your responsibilities or qualifications on your resume. Then you move on to creative excuses about why you were late or took an extra long lunch. Then you dream up a whopper to explain away your failure to turn in work on time… Rather than rely on lies to get you through, own your mistakes and take steps to correct them and improve yourself. That will make you look a lot better in the long run.

4. Playing the blame game.
If you spend all your time blaming others for problems, rather than looking for solutions, you’re going to be seen as a complainer and likely you’ll make some enemies with your colleagues (see No. 1). Putting others down just to build yourself up is even worse. Putting yourself down instead of actively showing that you’re learning from your mistakes isn’t humble; it’s kind of pathetic. In the heat of a problem or crisis situation, whose fault it is becomes irrelevant until the problem is solved. Be a problem solver rather than a blame assigner.

5. Being messy or disorganized.
It may seem that a messy desk doesn’t impact anyone but you, but it does. When your workspace is so messy that you can’t keep track of important things, it’s impacting your work, as well as those around you. When you are so disorganized that you forget meetings, arrive to work late because you lost your keys, or can’t hit a deadline because you can’t find your report, that impacts your entire team. Time management skills and organizational skills are widely taught and fairly easy to learn if you truly put in the energy. Even asking for help from your manager or HR department can reflect positively on you, because you’re recognising the problem and working to solve it.

In short, being reactive instead of proactive, taking responsibility and action instead of laying blame, and keeping your work activities and personal activities separate are the best ways to be successful and not let one dumb mistake ruin your career.