'Dear Sir, Your assistance is needed. I am the director of auditing at the Bank of [insert name of fictitious African bank here] and I have a proposition that will be very beneficial to both of us. It has recently come to my attention that a very large sum of money has been left in a dormant account at our bank belonging to a person who recently died in a plane crash. I am the only one who knows about this and I need your assistance to transfer this money. But there will be just a few expenses…"

So begins the infamous Nigerian 419 email scam which, despite being widely known and derided, continues to clog up inboxes worldwide on a daily basis. It is just one of the many ways that scam artists try to help unwitting people part with their cash. Their methods can range from the crude and obvious to incredibly sophisticated but if you are unfortunate enough to get sucked in, the end result is the same: you lose.

It is easy to think that in a media-savvy age like ours, people would be too clued in to fall for a scam but the National Consumer Agency (NCA) continues to field calls every week from consumers who are worried that they have fallen for a con. NCA director of public policy Maria Hurley says scammers continue to succeed because they are appealing to a fundamental aspect of human nature: greed.

"We all fancy the idea that we can get rich quick or at least make a few bucks with relatively little effort and that appeals to all of us to some extent. At the moment, because of the economic situation, a lot of people are desperately short of cash and anything that looks like it might offer the opportunity to generate an income could be worth a shot for many people. It is not that they don't engage their brains but people are genuinely in dire straits and very anxious about how to provide for their families and, as a result, they may be willing to explore avenues that they might not previously have considered," she says.

According to the NCA, the number one scam in Ireland is the premium rate con, where you are told that you've won a prize and to claim you must call a 1500 number which lands you with a massive phone bill for a prize that doesn't exist. However, the range of scams is extensive. Earlier this year, a number of people reported receiving calls from people claiming to represent an IT company which had discovered a problem with its virus software. The callers asked the victims to fire up their PC to reinstall the virus software and during the conversation asked for their bank account details – when victims refused to play ball, the callers became very aggressive.

Scams are not always so obvious though – some can seem entirely plausible and the victim can sleepwalk into them without realising what is happening. The work-at-home scam, for instance, promises you the chance to earn attractive sums of money while sitting in the comfort of your own living room – all you need to do is make an initial investment. Money that you will either never see again or which buys you a bunch of overpriced envelopes. There has been a surge in very sophisticated "phishing" scams recently – where the scammer sends you an email purporting to be from your bank. These emails look very credible and use the institution's logos and registration details but will invariably ask you to reveal sensitive information like your Pin number, which your bank is never going to ask you for. Even the traditional pyramid scheme has been adapted by scammers – now people are being asked to sell software to their friends with the promise that they will earn commission as more people sign up. The person at the top of the pyramid might make some money but very quickly those moving the software will never see a cent of commission.

The recession is also seeing an increase in the number of people calling to doors offering to carry out repair works in the home. In most cases, these will be legitimate business people but there are some unscrupulous operators out there. Do not be afraid to ask a tradesman for their details – an address and a landline – where they can be tracked down should an issue arise. Do not succumb to any pressure to employ their services immediately – if they can afford to tarmacadam your drive for a price today, they can do it tomorrow once you have checked them out. If you are employing a tradesman to do significant work, it may be an idea to check if they are adequately insured. Anecdotal evidence suggests that many sub-contractors are letting their insurance lapse, says Ciaran Phelan, chief executive of the Irish Brokers Association.

"Householders should always receive written confirmation that their chosen tradesman or small builder holds valid and up-to-date liability insurance. People who are insured with an independent broker should bring the evidence of insurances to their broker who will check it and make sure it is sufficient for the job in hand. While there may be a difference of a few hundred euro in the price between an insured and an uninsured tradesman, it could cost tens of thousands more if it goes wrong," he says.

Unsurprisingly, the key to avoiding any scam is to exercise vigilance combined with common sense. In the case of scams, prevention is definitely better than cure because in many cases the scammer is sitting by a laptop in some far-flung corner of the world well outside the jurisdiction of the gardaí and the EU's consumer rights watchdogs. Once you have handed over your money, the likelihood of getting it back is extremely slim. It is better to avoid being conned in the first place.

"It might be hackneyed but it is true – if something seems too good to be true, it almost certainly is. If you are offered something which suggests that you can make a massive financial gain or something for a price that seems extraordinarily good value, be suspicious and check it out. Go those extra one or two steps beyond what you might normally do and you could save yourself a lot of money," says Hurley.