Pay off any credit, in the order of the highest rate, so typically:
Credit Card ~18%
Car Loan ~7-13%
Do not overpay your mortgage, or skint yourself by a too short a term, if you have a credit card (which isn't interest free), or have car loans, you're literally throwing money away, thousands of it.
Once your credit card, or car loan is paid off, don't just think you can go and get something twice as good. Live within your means and work on other debt first. Even mortgaging to clear high interest debt can be good, 2% is better than 20%.
Don't think about debt by monthly payments, think of it like what is the total cost I'm going to pay/ owe, and divide that by the timeframe.
Like the cost of your car is:
Buy price - sell price (depreciation)
Maintenance/ Tyres etc
VED/ Car Tax
Work out what that will be, estimate the depreciation, fuel cost/ use, insurance etc and sum all of that up and divide by the months of your timeframe, that's your real monthly payment.
The dealer can make your monthly payment anything from £50-5,000, but it means completely zero, look at the total cost of ownership, it's all that matters in the end.
Don't use electric heaters, as electric is 3-10x more expensive than gas, per kWh, even with the current gas hikes (our electric comes from gas largely). But equally, don't heat your house, if you're only using a couple of rooms, turn some radiators off and shut some doors. Maintaining an "ok" temperature can be a lot more cost effective than your house going from freezing to roasting. Even reducing the temp by 1-2 degrees can make a massive difference.
Seal up any drafts in your house, like under kitchen units, behind the sink, bad seals on doors etc, this will help retain heat. Insulate the loft, doesn't need to be anything fancy, it all will help.