Second Panasonic breadmaker (ask family if they can buy you one for Christmas?) I use organic flour and get three loaves out of a bag of flour which is £1.85, if you used non organic flour it would be even cheaper!
Go vegetarian for a while! Might sound extreme, but our budget is about £75 per week for family of four and that is eating organic and shopping at Waitrose!
Eat lentil and tomato soup once a week, that is super cheap to make.
As someone as already said, jacket potatoes are very cheap too.
Use half the amount of washing liquid the bottle says.
Make big batches of cookies instead of buying packets, cheaper and you know what's in them.
Make batches of fairy cakes with a blob of glacé icing on top, again healthier treats treats then processed treats IYKWIM
Never, ever eat out, always take your own food and drinks.
Great cheap snack I front of the telly, home popped popcorn.
Before you write your meal plan for the week, look in all your cupboards to see what meals you can make from store cupboard/fridge.
Buy frozen veg over fresh veg, much cheaper and just as healthy if not healthy as all the nutrients are locked in when they are frozen.
Cut bananas in half to give to your little ones, and only give the second half once they've eaten the first so there is no fruit wastage and it gets abandoned after one bite! If they don't want the second half , leave it until later and slice the end off and it will be just like new! I've done this for a long time. If you think your child will only eat half an apple, rather than wasting it, cut it in half, lay un eaten half on a plate, when you return to it later on simply slice the side off and it will be ready to eat again with no brown bits. Or make large fruit salads to keep in fridge and only spoon out small amounts so you're nt throwing food away. Same with main meals, only serve what you know will be eaten. You can always go back to the kitchen for more if they clear their plates.
Don't use kitchen roll, used washable wipes.
Also don't use baby wipes to clean sticky hands after a meal, you can buy a pack of 7 cotton flannels at the pound shop and use warm soapy water to clean up and chuck in washing machine.