When it comes to holiday office parties, Ricky Eisen has seen it all.

The founder of New York City catering and event planning company, Between the Bread, Eisen recalls one employee, in particular, at a Christmas party she catered. The woman climbed on a table and started dancing. The party was on a yacht and waves, alcohol and dancing on tables are never a good mix: the woman fell and was seriously injured.

At another celebration, Eisen saw an employee drink so much that she vomited and started sobbing uncontrollably in the middle of the party. The woman’s boss ended up driving her home.

Office parties can be a recipe for disaster. But, with a little planning and self-control, it doesn’t have to be that way. Here are career experts’ six biggest end-of-year company party do’s and don’ts.

RSVP — either way

Even if your answer is no, you still need to respond. If you can, say you’ll attend — and actually show up.

“If you RSVP [yes], it is rude not to make an appearance,” said Eisen. Your absence may be noticed, even at a larger event.

"Business people" differentiate themselves from "business professionals" by their lack of attention to detail, wrote Cincinnati-based Ann Marie Sabath, founder of At Ease Inc, an international business etiquette training firm, in an email. “That includes not replying to office holiday party invitations.”

Worse is when people have the gall to be part of the “no show” list, she said. “The question that often runs through office party planners' minds is, ‘If that is how they handle internal client situations, is that how they also manage their external client affairs?’,” she said.

If you do need to cancel, do it professionally and with as much advanced notice as possible.

What not to wear

It’s a party. At night. At a local club. So a slinky skirt and low-cut top or a tight-fitting pair of jeans and t-shirt is okay, right? Not exactly. Think less about the venue and more about the fact that this is still a work-related function.

“Dress for success, not a nightclub,” said Roxanne Peplow, director of student services at Computer Systems Institute, Illinois. “Too often people dress very inappropriately for a work-related function.”

Peplow, who teaches professional development courses at her firm, suggests leaving the stilettos, mini-skirts, jeans and sports shoes at home. Tattoos and piercings should also in her opinion be kept out of sight. “Always have an executive presence,” she said.

Too many people dress “bar casual” and still expect to be taken seriously by their colleagues and manager the next business day, said At Ease’s Sabath. “Letting it all hang out is not considered appropriate holiday party garb,” she said.

Celebrate – but remember the rules of moderation

There’s nothing wrong with enjoying yourself at the party. But pace yourself, advised New York-based career adviser and author Vicky Oliver. If you get tipsy easily, steer clear of a free bar, be cautious about how fast and how much you consume. Eat something before you drink and start the evening with soda water poured into a wine glass to pass the time before you turn to alcohol.

“There's always someone at the holiday party who drinks way too much and behaves like a buffoon,” said Oliver. 

Also, overindulging, whether it’s food or drink, illustrates a lack of personal control and responsibility, according to Between the Bread’s Eisen. An “emotional hangover” can be just as bad, if not worse, than a throbbing headache, said Seattle-based Jessica Hagy, author of How to Be Interesting.

Bottom line: avoid anything that will leave you wondering, “What did I do?” the next day.

Mind your P’s and Q’s

Especially after a glass of wine or alcoholic punch, some people mistakenly believe that a good way to make a big impression on the boss is to buddy up like old high-school chums or try to impress with their best new idea.

“It's okay to shake hands with the boss and make small talk,” career advisor Oliver said. “But remain cognizant of his or her seniority and behave with the appropriate amount of decorum and respect.”

Equally as important: avoid the urge to gossip.

“The holiday office party is not a good time to share unkind remarks about the socially awkward IT guy across the room or the receptionist who has either gained weight or is pregnant,” said Oliver. Companies go to great expense to create events that celebrate you and your coworkers, and you’ll want to be gracious and positive in return. “If others are gossiping, walk away,” said Oliver.

“Foot-in-mouth disease can strike at any age,” said author Hagy. “Listening more than you speak is the only shot you have at inoculation.”

Be a team player

If your boss insists on a round of karaoke or a turn on the dance floor for every employee, try to resist the urge to run for the bathroom or the exit. Instead play along.

“Not only will you look like a real team player, but you will help bring others out of their shells,” said CSI’s Peplow.

Don’t refuse to participate for fear of making a fool of yourself or stand on the periphery mocking others. “Part of holiday fun at the office is to show a different side of yourself,” said career adviser Oliver. “Dance and sing, even if you do it badly. Your boss is inviting you to stretch and take a risk.”

When it comes to singing, pick a song that you know really well. “The key to karaoke is to pick a fast-paced song that doesn't require you to hold long, painfully off-key notes unless you happen to be a really good singer,” said Oliver. Your best bet is to corral a couple of co-workers and do it as a group. “That way you can ham it up on stage and not worry if you're singing out of key,” according to Oliver.

If something truly makes you uncomfortable, you can always politely decline. “Just make an effort to participate and encourage others from the sideline,” said Between the Bread’s Eisen.

Business and pleasure, still not a good mix

Holiday parties are meant to be social gatherings for employees to connect and enjoy each other’s company without the pressures of work.

“Business should be saved for the appropriate time, and bringing it up may rub people the wrong way,” said Eisen of Between the Bread.  

 “This is not the time to corner the head of your department so you can talk to her about the pressing issue you have with one of your clients,” said career advisor Oliver. “No one wants to talk business at a party, and it will just make you a social pariah.”

Instead, use the event as an opportunity to get to know some people who are out of your work comfort zone. “Mingle, smile and exchange small talk with as many people as you can,” said Oliver.

Career Coach is a twice-monthly column on BBC Capital in which we consider the career turning points and questions many professionals face. We welcome questions from readers at careercoach@bbc.com.