It requires a change of perspective. It has to start with: "This is my right, this is what I've worked hard for and if this is what I'm spending it on, then I hope to get exactly what's advertised from the product."
From that base you can start to ask for a discount or complain. If you have stayed in a hotel and the service wasn't what you expected, you should say something, and then ask for compensation, either a reduction in your bill or a complimentary meal.
People might complain but then not do anything about it, and just say: "Oh well, at least they apologised." But something should be done – you are paying, so you should get some form of compensation, whether it's 10 per cent off your bill or a complimentary night's stay.
Bargaining depends where you are. If you are outside the UK and travelling, you may find that people can mark up prices by up to 50 per cent, and you can expect to bargain for that 50 per cent.
Within the UK you usually pay a listed price, but hotel rooms can be an exception. You could try calling hotels, and ask: "If you're not full, and I want a room this weekend, will you offer a deal?" Hotels expect to fill their rooms, so when a hotel is below capacity, you can try to ask for money off.
In a shop, though, it's not the same thing, bargaining is not usually going to work. However, if you ask for your money back on something that is not right, you should get it.
Dr Tracy Alloway is a psychologist and director of the Centre for Memory and Learning in the Lifespan, Stirling University