Fifty years ago there were clear etiquette rules. For example, don't remove your sports coat or smoke your pipe around women, and never discuss personal affairs in public. But things have changed.
Today, people air their dirty laundry on Twitter and the sexes are relatively equal in relationships and business.
You can no longer be sure whether you'll be scoffed at or thanked for opening a door for a woman.
But that doesn't mean manners have no place in the modern world – in fact, if you want to make a good impression, etiquette is still the best way.
"Many would argue that rules don't exist anymore, but etiquette makes sure we don't give people ammunition to judge us on anything but who we are," says Marc C. Close, an etiquette expert and director of culture and art website RaraCurio. "And because so few people subscribe to these rules anymore, those who do stand out for the right reasons."
But how do you know what's archaic and what's still appropriate? We asked three experts to share their top tips on how to impress in tricky situations.
There are some obvious rules: don't drink too much; whoever invites should pay; and don't order the lobster unless your boss does.
But here are some more subtle tips to help you stand out from the crowd.
* Know your guests
"Good manners are about appropriate behaviour at the appropriate time, not blanket rules,” says Danielle Di-Masi, etiquette specialist with Click Training and Consulting.
"Some clients prefer fine-dining, but others might just want to grab a burger,” she says.
The key is making people feel important, whatever that involves. And brush up on cultural practices if you have guests from other countries. For example, present a Japanese client with a business card held in two hands and a slight bow.
* The handshake is still crucial
There's no getting around the fact a limp, wet-fish handshake makes a bad first impression, says Di-Masi. As a general rule, make eye contact, wait until your host or boss extends their hand and grasp firmly.
Another common bumble Di-Masi sees men make is to not shake women's hands. “Business should be gender-neutral – some men worry it's rude to shake hands with a lady, but it's rude not to,” she says.
* Put names tags on your left lapel
Same goes for lapel pins and boutonnières, advises Close. But don't wear more than one at a time.
* If you're the host, take charge
This is crucial, according to Patsy Rowe, author of four etiquette books including Manners for the Millennium. You don't want to go as far as ordering for your guests, but it's polite to suggest where people should sit, to drive the conversation and suggest how many courses people should order.
"There is nothing more impolite than allowing guests to feel lost and uncomfortable," she says.
* Don't remove your jacket until the host does
“Australian men have a bad habit of whipping off jackets, loosening ties and rolling up their sleeves as soon as they sit down,” says Rowe. Wait until your boss takes his or her jacket off or indicates you should do so, allowing them to set the tone, she advises.
* Don't order directly from the waiter if you're a guest
"There may be a budget you don't know about, or it may look like you're trying to take over," she says. "If you want anything, suggest it to the host and let them order," says Rowe.
* Brush up on your dining manners
Use cutlery from the outside in, hold your wine glass by the stem only (gripping the bowl warms wine, says Close), place your napkin on your lap when you sit down and rest your cutlery at the 4:20 position when you're finished eating. Also, don't burp or speak with your mouth full, and avoid clinking your plate or cups, advises Di-Masi.
* Don't fight over the bill
Fighting over the bill leaves a bad taste, Di-Masi warns. If someone else insists on paying, let them. Better yet, if you're the host, sneak away and pay before the bill comes, she says. "You'll look courteous and organised."
The first date
The aim is to avoid as much awkwardness as possible, and the dining rules above apply here, too.
One tradition that still applies today is that, generally, the man should offer to pay, says Close. But not everything needs to be so old-fashioned.
* Open the door for your date but don't pull out their chair
"If you're in a position to open a door then you should, whether it's for a man or woman," says Close. "But holding out a chair for someone is a bit grandiose."
Running around the car to open your date's door can also be awkward. Instead, he says modern chivalry involves waiting until your date has taken her seat before sitting, and standing when she leaves. "It's not about inequality, it's just good manners," he says.
* Don't bring a huge bunch of flowers
It's a nice gesture, but Di-Masi says it's important to come across as neutral as possible and flowers can seem a little eager. If you insist on bringing something, stick to a small posy your date can carry easily in one hand.
* Keep the mobile phone in your pocket
"It shouldn't be near the table," Di-Masi says. "Don't do anything that takes your attention away from your date.”
If you're expecting an urgent call, mention it at the start of the night so it's expected, she says. And if you do answer, converse away from the table.
Going to a wedding/dinner party/barbecue
There are basic rules – follow the dress code, make sure you show up on time – but brushing up on the finer points of etiquette will ensure you're invited to the next event.
Always send a reply, even if it's just a Facebook invite. "If you're putting on an event, you need to know who's coming, so it's rude not to," says Di-Masi. And if you do RSVP, try to show up.
"We often see people cancel the morning of events. That's not acceptable," she says. "Plan ahead – if you're attending a party on Saturday and are having the week from hell, let your host know mid-week you may no longer make it."
* Bring a gift if you're invited to someone's home
Wine and chocolate are common but convenient choices, says Di-Masi. Avoid flowers unless they're already in a vase, as they can take up the host's time. And if the situation is casual, text ahead to see what the party needs. "Bringing a $3 bag of ice to a barbecue will usually be more appreciated than a gift," she says.
* Buy a wedding gift the couple has requested
Don't get creative and give the couple a lamp if they've asked for cash. As a rule of thumb, you should be spending the amount your dinner would cost – generally about $100 a guest.
* At a formal dinner, don't take off your jacket
If you're wearing a dinner suit, never remove your jacket, says Close. "It's equivalent to a woman removing her high-heels – comfort should not outweigh your dignity."
* Send a thank-you
Finally, it's important to acknowledge your host's effort and tell them you had a good time, says Di-Masi, who recommends an email, Facebook message or text the day after the event. "As lovely as handwritten notes are, I'm a realist, and a text will usually do," she says.
What other rules of etiquette do you observe?