I've been married a long time and one thing I've learned is to keep my pantry stocked.
In the early days of my marriage, I would run out of flour, sugar or canned vegetables all the time. I soon learned that I actually could save money and time by watching for sales and stock up. I watch for 2 for 1 sales, then purchase one to use and one for the pantry. This only works if it is something we actually use and if the item's freshness date won't expire before it is used. For items that might expire I either purchase one saving half the price or buy both and give one away.
(Check your store to make sure they offer this pricing. Sometimes it is buy one get one free so you would pay full price for the first item whether or not you got the second item.) Also if the item is something you can't use before it would expire, consider giving the free / half price item to a food bank or an elderly or young couple that could use a little help with the grocery bill.
I shop at Kroger or Publix and have found their store brand items are generally just as good as the national brands. However, check the unit price every time. Sometimes when the national brand is on sale it will be cheaper than the store brand.
If I know I'm going to be baking, like at Christmas, I'll start watching for sales on sugar and flour. I'll buy these items when they're on sale even though I may not need them right away. When it's time to bake I'll have plenty on hand.
Finally I try to organize my pantry. I group the can goods together, so I know at a glance how may cans of peas, corn or tomatoes I have on hand. That also helps when I'm making my grocery list.
Just some common sense tips that I hope you might find useful.