Looking to cut your winter energy bill? You’re in luck. We’ve got just the market trick to make finding the cheapest deal easy and stress free.

It’s called the 15/10 rule of thumb, developed by Joel Gibson at One Big Switch, and it could save you hundreds of dollars a year on electricity.

Here’s how it works. Usually electricity retailers make extra money from customers who aren’t sure what the cheapest deal in the market is.

But thanks to the default market offer there’s a cap on what retailers can charge, and luckily all the other deals they offer reference that price.

Mr Gibson says you can quickly work out what the cheapest deal is by taking 15 per cent off the default price if you live in NSW, South Australia or South-East Queensland, or taking 10 per cent off if you’re in Victoria.

“The dozen cheapest deals in each state now conform to this simple rule,” he said on Thursday.

“We’re also seeing the cheapest electricity deals in years, but in many cases you need to shop around and switch to get the benefits, so households should cash in on this trend.”

The default market offer is about to change on July 1 and will fall further in line with plummeting wholesale electricity prices, so make sure you check what the price is in your area (see below) before finding a deal.

Source: AER (click to enlarge).

Making the energy bill call

You’ll still need to call your retailer to negotiate a better price though.

And that’s not always easy, Energy Consumers Australia boss Lynne Gallagher told The New Daily.

Ms Gallagher said despite being able to save hundreds with just one phone call, some people are reluctant to pick up the phone because they feel undeserving of a better deal, or they’re embarrassed.

“It’s actually OK to ring your retailer and say ‘I want a better deal than this’,” she said.

“You might think well I’m not poor or if I am poor I’m going to feel shamed by ringing them.

“It’s a good time in the next three to four weeks to ring your retailer and say … ‘You know what plan I’m on, do me a better deal than this’.”

The default market offer doesn’t apply to gas prices so in that instance it’s worth shopping around first, then asking your current retailer to beat other deals on offer.

Other ways to cut your bill

Rather than visiting commercial comparison websites to compare prices, which pay commissions to power companies, you can visit an independent government website, enter your requirements and be presented with a range of options to meet your needs.

Victorians can compare deals on the website Victorian Energy Compare, while elsewhere in Australia, except WA, you can visit Energy Made Easy.

Cutting your own power use is another way to trim your bills, but it’s important to focus on what is going to make the biggest impact.

Ms Gallagher recommends targeting three key areas: Heating, cooling and hot water use.

Heating and cooling each account for about a quarter of your yearly energy costs, while hot water contributes 15 per cent.

“I have had little old ladies come up to me and say, ‘I don’t cook a hot meal at night any more to save myself money’, and I go, ‘That is not saving you much money’,” Ms Gallagher said.

“If you change how you use your heating in winter, it can potentially make a big difference.”

Ms Gallagher said using an energy-efficient fridge, only heating the rooms you are using and doing your laundry at night, particularly if you have a family and are doing a load daily, can also help reduce your bill.

You can find the best contact numbers for each energy company, plus what to ask, on the PowerCall section of the Energy Consumers Australia website.