Oh, and when a couple give you their camera and ask you to take a picture of them in front of the Taj Mahal or the Sydney Opera House, remember that it's probably the only photo of them together on their honeymoon, so don't absent mindedly cut their heads off.
5. Using an iPad as a camera or camcorder
The ultimate tech faux pas? The iPad is a quite brilliant boredom-beater, but wielding an iPad above your sunburned head to film rudimentary video is the new sandals with socks.
Whether it's during a guided tour, a show at Disney Land, a sporting event or - worst of all - a gig where that 10-inch screen is an unwanted beacon of bright light, we nevertheless predicted this worrying trend years ago. After all, the two-gadgets-in-one concept is always hard to resist, and who wants to carry a camcorder?
Please just use a phone - it's more discreet, it's safer and it's far less intrusive. Or perhaps you are actually on holiday specifically to spend quality time with your iPad. If that's the case, point the thing at your own face and take a long, hard look at yourself (yes, we know it has a front-facing camera).
6. DSLR in one hand, smartphone in the other
You want to take a professional, nicely framed picture of your significant other in front of Buckingham Palace to keep forever on a hard drive when you get home. On the other hand, you want the instant gratification of about 10 meaningful 'likes' and perhaps a 'LOL' on Facebook, too.
So as well as lugging a DSLR across the globe you insist on composing the identical shot on your phone exclusively for uploading. If you're in a busy tourist spot, taking twice the time is likely to get you shoved out of the way, and rightly so.
Until all cameras come with Wi-Fi, like the Samsung Galaxy Camera, Panasonic LF1 and friends, why not try waiting a few hours or days and then just uploading your well-composed, considered pictures from the DSLR?
7. Obsessing about music and movies
What if you get bored? It depends what kind of trips you take, but any amount of lazing by the pool/long train journeys/killing time in airports demands a Plan B comprised of music, movies and books.
So a week prior to your holiday you get busy compiling playlists on your phone, stuffing it full of music, endless reams of podcasts, movies, TV shows and more.
But hey, guess what? Being on vacation isn't just about taking a break from the daily routine of work - it's also a getaway from all those digital distractions you fill up your home life with. We predict that you'll consume about 5% of what you actually travel with... and, no, you really don't need that just in case cache of 1001 Ebooks You Must Read, either.
8. Checking email while away
What did you do on your annual leave? Clear your mind? Or just your inbox? The smartphone is a misnomer on holiday and best left at home if you're the type who can't resist checking work email.
The logic is fool's gold; if you check email while on trips away, you can delete some ahead of time and get back to the office with a less-than-overflowing inbox. Whoopee.
If the checking of email on phones wasn't already almost a reflex action for many, it's about to get even easier with the price of data around the globe (especially in the EU) about to drastically reduce, which is the ultimate in false economy if you've spent hundreds to escape the daily grind. Besides, isn't an overflowing inbox the ideal excuse to take it easy on your first day back?