I started writing and was going to be witty and use an analogy about packing things away like a squirrel. I did a little research.
Don’t be a squirrel. They hid food all over. Forget where they put their nuts (thus why trees grow). And end up eating bug, small mice and other small ‘vertebrae’. Their food only has a small amount of shelf life, and if planted in the ground, again, trees grow.
I could tell you to be a pack rat. But frankly that is excessive preparation. This will cause spoiling of food and more than you would ever needs.
Canned goods like soups, fruits, veggies and canned meat would be best for the winter. Buying flour, sugar, rice would allow you to make your own breads and the rice can be used as a filler to stretch meals.
If you haven’t canned all your garden yet, now would be a good time to get that done too.
For more indepth information on must haves in your kitchen, consider the stocked kitchen by Sarah Kallio and Stacey Krastins. It provides a list of foods you can purchase and lots of recipes you can make with those recipes (great for the days you are stumped!)