Sometimes you might have to spend to save, e.g. the reusable wipes, cloth nappies, etc. Will be worth it if you stick to it.
Make big batches of soup/stews etc and freeze portions - great for lunches alone, packed or at home.
Shop at Lidl/Aldi every other time and stock up on cheap staples there, like fruit juice, tinned toms, cereal, muesli bars for packed lunches.
Buy reduced stuff which you can freeze (esp meat if you buy it) then plan menus around what is cheap. Always worth visiting the cheese/meat.fish counters in the supermarkets as they often have half-price reductions.
Make your own bread, cakes etc. Use your breadmaker/slow cooker etc.
Bills: We replaced our microwave recently and got a combi oven - we have hardly used the big one since and must be saving loads of leccy. It may be expensive to buy one specially, but if you have one, use it. Also never iron or use tumble drier!
If you do eat out ask for a doggy-bag - can't believe how many people I know never do this! We always do, and the kids and dh especially always leave something. (Not me!)
I have managed to save up about £2000 a year to either put in an ISA, or spend on a skiing holiday, and we are only average earners, so it must be working!