Most of us think we've mastered the art of supermarketshopping. After all we've been doing it for such a long time; we're bound to be experts.
In fact, the opposite is true: we've been doing it for so long that we now do the entire thing on autopilot. We wander the aisles in a trance, picking up things using a highly flawed combination of habit and whim.
It means we fall into a number of common traps, which when combined mean we end up spending 15% more than we need to. It means that before you head out for a weekly shop - or for a quick top up shop - it's worth taking the time to think properly about what you're doing, and make a plan, so you can steer clear of these mistakes, and save money on your shopping every time you go.
As a basic rule of thumb, the more time you can put aside before you go shopping, the better the bargains you will find.
If you have five minutes
This is long enough to check in the cupboards, the fridge and the freezer, to see what you have, and what you need, then write a quick list of the staples you have to buy.
If you have 10 minutes
In addition to a stock take, make a list of the meals you plan to eat during the week, and the items you need to buy in order to make those meals. Don't forget to schedule a leftovers day too.
Any extra time should be spent online. Mysupermarket.co.uk is an excellent place to start, because when you input your list, it will show you what your items will cost at each supermarket. If you're in a bit of a hurry you can visit the store where overall it costs less, and if you have a bit more time, you can split your shopping, so you buy everything wherever it is cheaper.
If you can simply steer clear of the most common mistakes in store, you can cut 15% or more off your shopping bill. If you can spare half an hour before you go, you can save another 10%.
It may be more effort than you're used to putting into your supermarket shopping, but it may just be worth the effort.
Shopping on AOL Money
Warning: chocolate crisis may be on the way
The best value wines in Britain revealed
Sainsbury's, Waitrose and Morrisons forced to recall products