I'm quite frugal, I do this.
I try all the basics stuff in the supermarket, if we cant tell the difference then we get it all the time eg stuffing, all my cleaning stuff, sanitary towels (tested them on my own), food bags, cat litter, tomato sauce, fizzy water, frozen veg, frozen rice, pikelets, muffins, mint sauce, rubbish bags ( I change the bag every few days so splitting isnt an issue) Sainsburys basic tea bags are really good, we've used them for over 12 months and dh hasnt noticed we dont have pg tips anymore (asda ones are rubbish though), jaffa cakes, digestive biscuits (you get the idea).
I go to homebargains for stuff like alur (made by the stardrops people bit like Woolite but only 89p), colour catcher sheets (their brand not dylon), cheap rinseaid.
I use one tablespoon of Daisy dishwasher powder from tesco, works out at 2p for a full load of dishes, if my maths are right.
I always take a packed lunch to work, I used to spend £3 a day, every day I do it I make a note in my diary so I can see how much I am saving.
I always park in the free side streets for 30 mins, long enough to do a home bargains and bank dash.
Anything I need eg kelp tablets I check on Amazon, you would be surprised what you can get on there. For the same price as 3 a day holland and barratt kelp I got solgar one a day kelp so it will last me 3 times as long for the same price.
I shop at asda and aldi.
I use the local farm shop for potatoes, 60p for 2.5kg.
I've just ordered the takeaway recipe book off amazon, so I can do DH tikka masala curries. I heard about it on moneysavingexpert.co.uk and it's only £3ish at the moment.
I looked at my washing machine instruction booklet and worked out which washing cycle used the least electric/water for cottons. You can save a lot doing that, some cycles are very wasteful. Ditto for the dishwasher.
Anything I need from town I check the poundshop, homebargains and wilkinsons for the cheapest.
Dh takes a tin of soup to work every day and bread for toast.
I check the local morrisons when I drive by for marked down bread etc.
When I renew my mobile tariff I plan to get one with a free gift eg TV, ps3, xbox etc and sell the free gift and the phone and put the sim in my iphone.
You can use nectar points in blockbuster, £2.50 towards a rental and when I shop online I check the nectar site first to see if they do nectar points, lots of them do even amazon then I follow the link and it all adds up.
I check my asda reciepts online on their price checker and often get vouchers, if I see a reciept in a trolley I pick it up and check that one too .
So there you go. Now you know how really sad I am!!