They come in many guises and we’ve all been prey – or at least witness – to some of them at some time or another. Cheap tricks and scams surround tourists and travellers like trinket peddlers round an air conditioned coach, and much of your time in many places will be spend trying to dodge them.

Some, like the fake police ruse or the over-enthusiastic money changer, are relatively easy to spot and avoid, but others are more pervasive. My particular bugbear is the “chance to visit a factory” bolted on to many a journey to somewhere more interesting, where the “factory” is in fact a few poor artisans toiling behind a glass screen in the annex of a yawning gift shop - all the more annoying as it’s practically unavoidable.

I’ve been to more of these attractions than I care to remember. The jade factory in Beijing was a particular annoyance, a mandatory stop on the way to the Great Wall of China, where a handful of uninterested workmen could be spied on the way into a palace of unaffordable sculptures. I had no intention of coming home with a six foot Spanish galleon for my London flat, but I had to spend half an hour looking at them – and swatting away GBP-enamoured salesmen - nonetheless.

A private driver in Marrakesh, meanwhile, turned out to be a whistle-stop tour of hard sells masquerading as education. Within a hectic morning we visited carpet workshops (a deserted loom left in the corner of the room full of rugs and overbearing assistants), argan oil cooperatives (five local girls crushing nuts on the floor and a sixth whisking us around various bottles for sale) and a "craft fair" that looked suspiciously like a Moroccan version of Habitat.

Other tricks I’ve fallen for once and learnt a lesson. The “helpful porter”, encountered in a daze after 11 hours of Virgin Atlantic at LAX, who helped me navigate the disorientating motorway that is the arrivals area, then demanded a $20 tip in return is one bitter memory.

Some are obvious, especially to anyone who’s had a even a cursory read of their Rough Guide on the way over, and yet no less irritating. Take the Beijing Tea House Hustle for example. You know the girls approaching you on Wangfujing pedestrian street only want to drag you into a tea shop to spend a monthly’s salary on an elaborate series of infusions, so you speak gibberish back to them, but they’ll still be there tomorrow. I probably made it worse for myself loitering with a camera so many times.

What are your worst tourist scams? Which have you fallen for, and which have you seen coming from a mile away?