Whether it's a formal office party your boss hosts or a casual barbecue at a coworker's house, a work-related social gathering isn't strictly social. The impression you make at the event will impact your job -- for better or, potentially, for worse.

"These [people] aren't your friends; they're your colleagues," stresses Marjorie Brody, founder of Brody Communications and author of Professional Impressions: Etiquette for Everyone, Every Day.

So how do you balance having fun with the fact you're technically still at work? Follow these tips.

If your firm's president is having a companywide gathering at her lakeside cabin on the outskirts of town, blowing it off is not an option. If you value your job, you need to attend such an event. In that situation, "no-shows are noticeable," says Diane Domeyer, executive director of staffing company OfficeTeam.

On the other hand, if you're invited to a coworker's wedding and you don't consider her a friend, feel free to respectfully decline, saving some of your precious free time and avoiding the possibility of a major faux pas that might impact your job.

"If you're clear about the people at work you consider personal friends versus those you view primarily as business associates, deciding whether or not to mix your business and social life is less complicated," says social psychologist Susan Newman, PhD, author of The Book of No: 250 Ways to Say It -- and Mean It and Stop People-Pleasing Forever.

Don't Overdo the Refreshments 

Overeating at a company social event will earn you a "less-than-complimentary nickname and a reputation for greediness," warns image consultant Dianne Daniels.

And over-imbibing "is even more deadly to your office reputation, because your secret -- and not necessarily complimentary -- thoughts about your coworkers, boss and job are more likely to come flying out of your mouth when you've had too much to drink," Daniels adds. So if you choose to imbibe, limit yourself to one drink.

Dress Appropriately  

While you don't necessarily have to dress business professional, the company social event is not the place to try out your new, over-the-top outfit.

"You don't want to show too much skin, either," Brody says. "Leave your bikini, your Speedo and your short, short, short skirts/shorts at home."

Don't Haunt the Bigwigs 

Sure, it's nice to have the chance to get to know your company's executives better. "But remember that an overly friendly or aggressive approach will have people backing away from you," says Daniels. "Take the opportunity to be seen and say hello, but don't chase executives or higher-ups around the venue trying to impress them."

If You Can't Be Positive, Be Quiet 

No organization is perfect, and we all have at least a few work-related frustrations to vent. Just remember: The company social event is not the place to do it. "You never know who's behind you in the buffet line or at the next table who might overhear your negative comments," warns Domeyer.

Socialize Outside Your Group 

What you view as hanging out with your normal group of coworkers might seem like sophomoric, cliquish behavior to others. So while it may not be much fun, especially if you lean toward introversion, do your best to talk, if only briefly, to lots of different people at the event.

"Say hello, and try to imagine doing a figure-eight around the room, greeting as many people as you can in the hour or so that is allowed for the meeting," says Michael Ray Smith, PhD, a communication professor at Campbell University. "Don't find one person and just sit there. That's not only rude, it's a career-buster."

Thank Your Host 

In a world where gratitude is often in short supply or even nonexistent, expressing your appreciation to those who put the event together is not only a smart career move, but it will also make you stand out as one of the relatively few employees who hasn't forgotten how to say thank you -- be it to coworkers, bosses, or your firm's all-important clients and customers.