I normally time my visits to the supermarkets to just before closing, when they have lots of great reduced price stuff waiting for collection. Generally speaking my neighbourhood has more poorer people than the surrounding areas so these bargains are gone quickly. My trick has been to cross over to more affluent neighbourhoods where the pickings are much richer. I also do this when I after visiting friends in other parts of the city.
Often I can pick up loaves of gourmet bread that normally sell for £1.20 each for around £0.30. I then normally slice this up and freeze it. It makes great toast - good sourdough bread or wholegrain with herbs beats tinned white loaves any day! Since I don't have time to make bread for myself this is the next best thing cost wise. I also pick up fruit and salad at half price, and reduced price fish, which I normally freeze when I get home. The salad and vegetables are normally good for at least another 2-3 days - generally I find the supermarkets paranoid about best before dates.
So when I shop, a meal plan for the week is not normally something that I do beforehand, it's something that I decide once I've found a few things (at a reduced price) at the shop. My freezer is full of half price or less food which is great
Anyway, I was wondering if anyone else wanted to share their badass supermarket tricks and also where you make big savings food-wise.