Hi Grem!
I live in the UK and I feel it's a bit harder here to save higher percentages of my income compared to the US stories. But let's keep going, we will get there!
First, for mobile phone, I use Giffgaff, it runs on the O2 network and works well for me. I pay the £7.50/month, have a look at their deals, I believe it's the cheapest on the market and you keep the same number if you switch.
Food: what works for me is to shop online at Asda and buy loads of cupboard and freezer food. This works for two reasons: one you can see how much you are spending and control that and the other is that you will have plenty of food at home and avoid frequent trips to the supermarket (I can't resist adding more and more things to my basket).
It's good to have staples like rice, pasta, canned beans, canned corn, tinned tomatoes, tinned tuna, frozen spinach, frozen courgettes, cheese like feta can last many months in the fridge if not opened.
As someone said, meat is expensive, I've reduced the amount of meat I eat but mainly to give space to more vegetables so it's healthier and cheaper in the end.
Don't think you are being cheap when you are food shopping, you might feel that you are depriving yourself and it will backfire; think instead that you are trying different things and being more healthy.
Now, it says a bit everywhere in the blog/forum that you should target your 3 biggest spends so I'll reeeeally look into that £316 random stuff, is it going out? house gadgets? kids toys?
Is £75 for virgin for TV and internet? I'd ditch the TV (so many ads!!!), watch stuff on the computer and payu maximum £30 for internet/landline.
I use moneydashboard to track my finances.
Hope it helps!