We're not quite in that ballpark but maybe quite close in terms of what we spend. We live quite a hippy/frugal life.
Some things that I think help.
Buying second hand clothes on ebay. You can really save a lot, especially on kids clothes and as a bonus, it's better for the planet.
Reuse and repair things you already have. Buy anything you need second hand, as long as it's realistic to do so.
Fuel economy. Have a look at what you are driving and, if you own your cars, maybe look into whether it would be cheaper to sell what you have and buy or lease a smaller car with better miles to the gallon.
Ditch meat. I don't eat meat for ethical reasons anyway but it's also much cheaper to bulk out meals with lentils than meat, for example.
On that note, avoid convenience food and buy staples and make from scratch instead. Microwave meals, buying lunches and coffees on the go etc add up to massive amounts over time.
Find joy in nature. A picnic, a park visit, a long rambling walk can all bring a lot of fun and joy.
Recreate the pub or restaurant experience at home. A £5 pinot noir from lidl is far nicer than a 14.99 bottle of pub wine and you can still have friends and nibbles in your back garden. Cheaper, nicer alcohol, no taxi fare and no drunk strangers or shit music.
Similarly, you don't need a gym membership to work out, you can keep fit at home with minimal or no equipment. Resistance bands are great and so is youtube.
Look at all of your outgoings and use a compare the market or similar. Can you save on car insurance? Energy or phone bills? Consolidate loans for lower monthly payments? Ditch subscriptions you're not using?
Have a clear out and use it as a way to make money. You probably won't make a fortune from sticking things on ebay or Facebook marketplace but you never know and it's always nice to declutter and give things a new lease of life elsewhere.
Hope some of this helps. :)