Lots of fantastic advice already written.
Rentals for your own space is prob the best, have a look at new build apartments, a lot of people bought these at full price from the mass company but now that they are trying to sell them can't get back even 80% of the purchase price and so have put them up for rent at a reasonable rate. Also have a look at older style properties sometimes things that are a bit run down (old) go for cheaper. I'd also go with something that is furnished so you don't have to furnish it yourself. If the property has had a good run of tenants then previous tenants tend to leave some of their belongings behind - pots, pans, table wear etc
As for food, the good wholesome food can't be beat! I invested in a crockpot (I would try and buy one cheap at a car boat or eBay or even a discount site) an example of food I cook is - I make a bolognaise with a big pack of mince, carrots, celery, onions, garlic, tinned toms and a beef stock, adding the vegs really bulk it up when it's been cooking for a few hours I blitz it so it becomes a ragu then add a shed load of mushrooms. So I spend approx 5.00 on ingredients and it makes 10-12 meals! That's makes dinner around 50p a portion. Also bulk buy pasta, rice and potatoes!
As for fuel you can check which is the cheapest garage in your area before you set out. Keep an eye on when tesco are doing the fuel deals but be careful your not buying unnecessary food items to get the fuel discount that ends up not being cheaper because of what you bought in store (hoping that makes sense lol)
Heating costs at home - shop around- nothing beats shopping around! And when with a company make sure you are in their best possible rate! I would also advise investing in some decent snuggly blankets that you know will keep you warm- layers and blankets are your friends, instead of running your heating all the time to keep you warm have it at set times that you need it most and just wear warm layers indoors (I don't mean a coat, scarf etc lol)
If you still wish to maintain a social life but are worried about costs and hate saying no I can't do this or that, invest in a cineworld card- it's 14.99 a month and is unlimited to the amount of movies you can see. Advise friends to do the same so that while you can see your friends and the latest movies you aren't spending a small fortune for each night u see them. Also groupon sometimes have deals out etc and a lot of food places have deals aswell so if meals are planned out with friends, have a look for a voucher before you go out to see what deals you can get. And don't be embarrassed about it, it's the done thing now to produce vouchers at restaurants- they need your business more than u need their food!
Last but not least start to save money! I know that when you are budgeting the last thing you want to think about is trying to save money but emergencies do arise and instead of it making a massive dent in your months pay packet, savings set aside for emergencies can be used to cover the cost without Breaking you.
All I can say is good luck xxxx