0% - good for you. The problem is no longer growing and is starting to shrink!
essentials of life: food, shelter, warmth, water, clothing, insurance, council tax. Fortunately you are in the UK and education and health care (the other essentials) are free. I also think that internet is essential as it helps you save money. Mobile internet is a luxury, you do not need a smartphone on a contract.
a mobile phone is handy - but it must be a simple pay as you go job. £10 credit should last 2 months or more.
Christmas is NOT essential. If there is a bit left for presents for the kids, fine -if not, so what? Put the radio on, go see some Christmas lights, listen to some carols etc etc.
obvious no-nos: Sky, DVD hire, (so cheap on ebay/charity shops) hair colouring, beauty treatments, magazines, newspapers, takeaway coffees, perfume, new gadgets, subscriptions to anything, new books (library is free and I just love being able to grab whatever I want there)
food; plan it, never waste it (you should be throwing away nothing except peelings and bones).
clothing; charity shops except shoes. Adults only replace clothes, don't buy extra. You don't need that much.
warmth: more clothes on, shut doors, draw curtains, use draught excluders etc.
travel; under 2 miles and you walk if you are able bodied.
socialising; so many people just don't get it. Time to be frank and simply say 'we aren't doing xxx because we can't afford it at the moment' and think of alternatives. I have a much lower income than many of my friends and I agree it is hard to get people to understand.
good luck.