As far as frugality goes, a lot of what circles the English-language Internet is based on life in the US. So when you move to a country that only intermittently believes in the existence of coupons, where the stores aren't the size of entire city blocks, where your closets are slightly biggger than a litter box, scenes like the clip below become more than merely grotesque, they're horrifying.
It's not so much that they've saved 90% off their bill that's horrifying--actually, I'm kind of envious of that bit--but the fact that they could buy almost $900 worth of...well, stuff. I'm sure most of it is non-perishable and most of it is useful--hell, I hoard cat supplies and personal hygiene things--and will be used in the end. But there are other "extreme couponers" who build stockpiles of hundreds of bottles of shampoo and thousands of sticks of deodorant, and all you can think to ask when you see it is, "Why?"
However, if saving money is equivalent to not wasting money, then food waste is a good way for all of us to begin pinching pennies. The average American wastes 25% of the food that he buys; if you include the bits that get tossed in industrial processing, it goes up to 40% of edible food going literally out the window. There's no reason to think that Europeans do much better, either: a study in the UK indicates that Brits and Europeans in general also end up tossing about a quarter of their edibles, and if industry gets factored into the equation, waste goes up to 50%. So that means, of the about €350 I spend every month on groceries, a full €88 of it gets trashed as waste, and that there could, in theory, be almost twice as much food on the supermarket shelves. Survivalist pundits have it a bit wrong: we don't need more food, we need not to waste the food we have.
I don't waste 1/4 of all of our food, that's for sure. But I'm not entirely innocent, either. By my estimation, about €20-30 of food gets tossed every month. But even so, that's a lot of money that gets wasted--enough for an extra winter of heating bills, two or three vet visits for all three cats, a hospital delivery and the kraamzorg that follows, or an extra month's worth of groceries at the end of the year. And the scary thing is, it used to be a lot worse.
I use a white board with a permanent grid (similar to that one) to plan out our meals and keep up with Karel's peripatetic schedule of shifts--not only does he work a variety of shifts, his schedule frequently differs from the roster he receives every month, so I also need to consider what he needs to bring for his brown-bag lunches-that-aren't-always-lunch. I do try to plan meals around the grocery flyers--if wraps are on sale, then it's burritos and quesadillas that week. Right now, tomatoes are a bargain, so it means lots of salsa, gazpacho, and salads.
To be quite honest this whole endeavor isn't so much about saving money as it is about not wasting any. It's a major pet peeve of mine that I inherited from my mother, but my mother would also cook the same dish, literally, over and over again, until the food was used up--which, I can assure you, would lead to a culinary mutiny on Karel's part if I tried that. Waste isn't just lost money, though. There's an inherent "goodness" to good food that gets lost every time we let something rot, a bit of potential that gets lost in the garbage. To arrive at your house, food has had to be grown, to pass through hundreds of hands, exchanged for money--letting that all go to waste, as easily as we do, is the real scandal.