The online shopping, which we can do monthly works really well for us. We buy all our "normal" stuff from Tesco (we don't have an Asda, otherwise we would use that!) and our frozen stuff from Iceland (free delivery). Any fruit, veg, etc we buy from Aldi. I go and do all the shopping (yep, me - I hate shopping!) and I reckon it is saving us almost £50/month from not picking up bits of rubbish that we end up throwing away. The clubcard points and online vouchers work really well. Our Tesco shop was £14.50 cheaper than last month's because of this! Plus, we got our vouchers, so I toddled off to Tesco and purchased Sugar, Cheese, Indian sauces and Bread and got myself an extra 200 points! That's a further £2 off my next shop.
The BOGOFs work if you know you will use your free item. For example, we often buy baked beans (£1.46 each, or 2 for £2.) - beans don't go off until 2010, so that works! I would never buy something with a short shelf-life that was BOGOF (i.e. bread) because we end up chucking the free one, because our freezer is full!
Another tip - my Mum and Dad buy all our meat from the market. A sackful of chicken breasts for a tenner. They last us a month! Far, far cheaper than any of the supermarkets (although Iceland do a reasonable 5 pieces for £3).
It's all about shopping around to find what works best for you. We have full shelves and a nearly full freezer at the moment, so our next shop (next Tuesday - pay day!) will probably be a very cheap one and given we have a week in Southport, it will probably be next to nothing!
I wish I had the patience (and a garden!) to grow my own produce! [:p] My Dad grows his own stuff and it does taste so much better! [8D]