meal plan!
we have a 4 week rotating meal planner and at the start of the month i spend 100 pounds ish on all the dry ingredients, then maybe £30 per week for the other 3 weeks to top up on fresh food. we buy exactly what we need, and no wasteage, also cook double portions that are frozen for a meal the following week. there is no 'what shall we have for dinner' panic, no arguing between the kids about what they want, they go and look on the fridge and read what it is and they know that's what they're getting.
in this way we can buy food, toiletries, cleaning products and nappies for me, dh, ds (5) and dd (2.10) for under £250 per month.
before we did this we spent approx 80 per week, and ended up buying top up bits and takeaways when we didn't have anything in.
Also, leave oven door open after cooking so the heat warms up the house (we did this today, the house was quite chilly but warmed up considerably quite quickly)
turn electricals off at the plug (wish i could get my dh to do this)
line all your curtains (doing mine with cheap fleeces from ikea) and draw them at dusk to keep the heat in.
make christmas and birthday presents, and/or buy stuff in the sales and keep in a present box
will think of more no doubt, saving money, my current obsession!!