• Perfect planning makes for a smooth trip
  • There's no harm in asking for an upgrade – but be polite
  • Go beyond Google and get a local guide

1. Cutting it fine at the airport

Try to be punctual, especially if you're crossing continents. After all, you won't necessarily get your airfare and other expenses back if you miss your flight due to poor planning.

'Long-haul flights use large aircraft that can hold over 600 passengers, so check-in starts early to ensure everyone boards in time', says Jonathan Coen, Customer Relations and Service Director at Heathrow Airport (@HeathrowAirport).

2. Bringing too much carry-on luggage

The rules vary, so always check – you don't want to be the traveller having to unpack your carry-on bag at the gate because it's too big.

'If you're travelling with kids, encourage them to carry their own small backpack of must-haves', says Nadine Mellor of family accommodation specialists I-Escape With Kids (@iescapewithkids). 'This helps them learn the art of packing – and frees up space in your own bag.'

Have a look at Skyscanner's handy chart with the cabin luggage allowances on most of the major European airlines before you pack. 

3. Badgering the check-in staff

When it comes to asking for special treatment, the key is to be polite, and accept it if nothing comes of your request.

'These days, it's very unlikely you'll be offered an upgrade at check-in', says Alex Malcolm, MD of Jacada Travel (@JacadaTravel). 'There's no harm in asking, but it's about the way you do it – if you ask politely, with a smile, you stand a greater chance.'

4. Slowing down the security queue

'Heathrow passengers are some of the most organised travellers you'll meet', says Jonathan Coen, Customer Relations and Service Director at Heathrow Airport. 'Frequent flyers like to pre-pack their liquids in a clear bag and wear shoes without laces to make their journey through security even quicker.'

The added advantage of bagging up your liquids is that it protects the rest of your luggage from spills – you may not be covered if your favourite cashmere sweater gets stained by nail varnish.

Passengers at Stansted, meanwhile, are not the ones to blame for recent queue-related issues: the biometric passport scanners have been playing up because of the setting sun. The direct sunlight makes it harder for the system to read faces, robotics expert Ralph Gross, of the Robotics Institute at Carnegie Mellon University in Pittsburgh, told the Guardian.

So you don't hold up the queue yourself – technical issues aside – make sure you have all your documents to hand.

5. Over-indulging before a flight

If you're not travelling with the kids, you might be tempted to toast the start of your trip. Remember, moderation is key – not least because an aircraft cabin's low humidity can deliver a thumping hangover.

Between July 2016 and July 2017, 442 people were held on suspicion of drunkenness on a plane or at a UK airport, according to figures obtained by the Press Association.

This is obviously the extreme end of the scale, but any drunkenness in an enclosed space six miles above the ground is aggravating.

6. Letting the kids run riot 

Occupying your kids during journeys could save you from some withering glares, but more importantly it will help get rid of any excess excitement.

'Exercise is key, especially for toddlers', says Kathyrn Brierley of The Healthy Holiday Company (@healthyhols). 'On trains and planes, try and balance time in the seat with time walking up the aisles. Make each trip an adventure.'

Nadine agrees: 'Plonking kids in front of screens for too long only stores up trouble for later – not least because they won't sleep.'

7. Getting annoyed at the space hogs 

We've all seen them – the scoundrels who recline their aircraft seat so suddenly they spill your drink, or the selfish sunbed stealers who dump their stuff before sloping off. It's best to keep calm and let the airline or resort staff have a quiet word. 

'Life, not to mention your holiday, is too short to get bothered about things like that!' says Alex.

8. Not being green

In a 2016 World Travel Market survey of British holidaymakers, 79% said environmental issues were an important consideration in their choice of destination. Despite this, some people let their eco-friendly habits fall by the wayside while they're away.

'Did you know that the plastic bottles that end up in our oceans can take 450 years to break down?’ says Justin Francis, CEO of Responsible Travel (@r_travel). 'If you do nothing else, travel with re-usable shopping bags and water bottles.'

9. Not venturing beyond the hotel

Long after the memories of those lazy afternoons on the beach have faded, you'll still remember the hilarious taxi driver who took you to a village football match. Adventurous tourists also help boost local economies.

'In developing countries, buying direct from craftworkers and fruit sellers can make a real difference, creating better places to live in and better places for people to visit', says Harold Goodwin (@goodwinhj), MD of the Responsible Tourism Partnership.

10. Believing Google has all the answers

'The internet is chock-full of free advice, but much of it just isn't reliable', says David Else, travel writer for Lonely Planet (@lonelyplanet). 'In contrast, guidebooks are created by professional travel writers, who check locations anonymously and honestly.'

Justin recommends hiring a local guide: 'If you only visit TripAdvisor's top ten places, you'll spend most of your time with other tourists', he says. 'With a guide, you'll get closer to local life and have a much deeper travel experience.' 

11. Wriggling out of learning the lingo

'By giving the local language a try, you can form an instant connection with people,' says Alex. 'As well as basics like 'please' and 'thank you', try to learn a quirky phrase that makes people laugh. Even if you don't say it right, they'll probably appreciate the effort.'

12. Forgetting to switch off 

'We should make more time to sit down, put our phone or camera away and just savour the moment', says Justin. 'Sometimes you see more by staying quietly in one place rather than rushing around.'

One last thing...

Before you go on your travels, make sure that you've taken out the right holiday insurance for the activities you might be doing. You don't want to miss out on something exciting just because it isn't covered by your policy.

Plan ahead, be polite and put down your phone once in a while and you can be sure that not only will you enjoy your trip, but the holidaymakers around you will as well.

Follow Emma on Twitter @Emma_Gregg for more stories and tips from her travels.