Up until around six months ago, we used to buy in bulk many foodstuffs that can be stored for a long period of time. That includes pasta, rice, canned foods, dry beans, etc. We accumulated quite a nice stockpile of food that was bought at very good prices.
Building and keeping a stockpile is recommended, but of course, it will only work if you have at least some spare cash each week to buy more than you need at the moment. Right now, we keep our grocery shopping to a minimum, and eat a lot from our stockpile. This really helps to reduce the grocery bill.
When things get better, financially, I hope we can replenish our stockpile again. We'll keep an eye on those non-quickly-perishables at good prices, and buy some for immediate use, and some for stockpiling. Some of that stuff can last for years. Just one caveat: each year before Pesach, we need to get rid of the items that are not kosher for Pesach. Last year, it meant giving away a pile of pasta.
There is really something very comforting about knowing that you have a lot of food in your house, food that can tide your family over in tough times. Having a stockpile may also reduce the frequency of shopping, which saves money and time.