Lots of use of discount/offer coupons & vouchers.
My main memory is getting free/cheap train tickets from collecting labels from cereal packets and washing powder - our cupboards were full of packets of them so we could go on train trips every weekend. I seem to remember being able to go to London for a pound virtually every weekend one year.
Never bought food on the journey or when we were there, Mother would always make a bag of sandwiches to take with us for both lunch and tea! Whether days out on the train or family days out in the car to seaside resorts etc - the bag always came out and sandwiches passed around at meal times!
She was always cutting out coupons from the papers and studying the leaflets pushed through the door from local supermarkets.
Plus religiously buying stuff from where she'd get either Green shield stamps or co-op stamps, then sticking stamps in the books, and accumulating them to buy pretty impressive things like a hi-fi. I seem to remember Tesco gave out green shield stamps so was our main "go to" supermarket.
Not to mention choosing where to buy petrol for the best vouchers to get glasses and other things.
Basically, all our shopping was dictated by vouchers, discounts, or other forms of incentive schemes.