I have a very strict budget. This is how i work it:
I list everything I recieve (wages, WTC & CTC, CB, maintenance etc), for the month.
I then list out all the 'have to pay' expenses for the year - water, electric, gas, council tax, car tax/insurance/MOT/service, child care costs, phone bill etc. Work these costs out over the year and then divide by 12 to get an average monthly amount (fuel bills are more in winter etc so come winter I have extra put aside when I overpaid in the summer). I then transfer that amount each month to an esavings account. I can only access it online and I can only transfer money from it to my current account. When a bill comes in I transfer the money from the esavings account, put it to my current account and immediately pay the bill.
I used to pay all my bills monthly by standing order, now I'm working i find it better to do it this way as I rack up some interest which can sometimes be as much as £30 to £50 a year!) Also my biggest hit for childcare is in the summer hols, this way I am putting towards it all year round, and the money is there when I need it pay for it.
I put a small amount aside for emergencies. This goes into an ISA account as the interest is better and means I really have to think twice before taking it out. This is for things like when the washing machine packed up or the bathroom toilet started leaking, and when i needed new tyres for the car. Just this week my hoover packed up! I couldn't afford things like that if i didn't put money aside like this. I refuse to borrow money because the interest is just wasted money imo. If I can't afford it I simply have to wait till I can. I did used to buy stuff like this from Kays when i was on IS as you can pay it over 20 to 40 weeks. But it does tend to be more expensive than shopping around can be.
I have quite high travel expenses to work. I budget for my monthly work petrol and parking costs, and then I put a further amount aside for 'other petrol', so to get to the shops, weekend travel etc.
I then work out what I have left. Put a reasonable (livable) amount to grocery shopping. For me and ds this is now £45 a month, which is pretty decent I find. It used to be £30 when I was on IS.
I then put aside for other 'necessities' such as clothes. I rarely buy anything for myself, and most of my son's clothes come from friends/family. School uniform, PE kit etc can't always wait for a hand me down though and I do have to look 'reasonably presentable for work' so do have to buy some clothes new occassionally. And I do buy ds new shoes, but I wear rubber flipflops myself most of the year which are far cheaper than shoes!
I then have 'other' expenses which includes outings, luxury grocery items , expenses for my son like scouts subs and camp or swimming lessons. That is a fixed amount each month. If i need extra food money I take it from this 'other' pot. If the pot is empty we don't go out and we don't get any luxuries or un-necessary items.
As for xmas, I get my WTC & CTC paid every 4 weeks. Come December i get a 'double' payment. So I use that 'extra' for xmas food and presents. I don't include the 13th payment in my income calculation.
We don't live a life of luxury, but we do get by. I rarely go out in the evening, we never have takeaways except maybe pizzahut a couple of times a year, and I don't drink or smoke, we don't have sky. My son doesn't get pocket money either though as he's now 9 i'm having to look at that again and will have to juggle my budget a bit.
I have to be very disciplined and when a budget is used up that's it, no sneaking it from a different budget. I can do this, but if you can't then you might want to look at paying all your bills monthly by standing order.
Also some have said use cash only. I personally don't carry cash and put everything on my creditcard. I pay that off every month by automatic direct debit though so never pay any interest. I do this because I had a cashback creditcard and never spend more than I have budgeted. I wouldn't advocate a creditcard otherwise. If I have cash in my purse I spend it, therefore if I have none I can't spend it. I know what my budgets are, I am mentally adding up as we go round the supermarket and am not afraid of saying sorry i have to put something back if i miss-count!
This method works for me because I am strict and stick to the budget religiously. I may have money in the bank when I look, but that doesn't mean I have money to spend.
Whether this would work for you depends on how you and money work. Maybe there's some things from it you can apply to your situation. Definitely agree with those who say list what you spend for a month and see where you can cut costs.
Best of luck
Gilly