Grab the trash, two empty paper sacks and some damp paper towels, it's time to get all your non-chilled foods in order.
Begin with the space where you put the boxes & cans so that if you don't do everything today, you'll at least have gotten the main stuff tidied up.
Pull everything out of the cupboard or off the shelf, tossing the spoiled items in the trash as you go.
Wipe down the surfaces with the paper towels. Spills attract vermin, so make it non-gross.
Now go through the collection of foods. Anything you realize you'll never actually use, but which isn't past its sell-by date and is unopened, goes in one of the paper sacks for donation to charity. Anything else still good that you realize you don't want, but which has been opened, should go in the other bag to give to friends/co-workers or in the trash. Yes, if you won't eat it and you can't think who would then throw it away and be wiser when you're shopping in future.
Okay, here's the fun part. Look at what's left and group it into the same kinds of foods. Now arrange those things together back in the pantry with the oldest package of any type of food at the front of its stack so it gets used first.
For example, in my big kitchen cupboard, I have from left to right on the bottom shelf:
– oils and vinegars
– canned tomato sauce & paste
– pasta & polenta
– boxes of Annie's Mac & Cheese
– cans of various kinds of beans
– potatoes and onions
– cans of meat (tuna, chicken)
– to-go items (breakfast bars, lunchbox-size applesauce, Fig Newmans, rice cakes)
– lentils, barley, etc.
– quick soup packs
– bottles of Clamato
When it's time to go shopping, I just scan the cupboard and can tell at a glance if I'm running low on any staples because they're all grouped together. No more buying things it turned out you already had plenty of!
Get your pantry act together and you'll probably also find you cook and pack a lunch more often. When you are hungry and take a look, seeing the pasta right next to the jar of sauce will probably remind you that you have an easy option a lot faster than sending out for pizza.