There are so many substitutes for all kinds of every day things. Some things are just common sense and others involve really thinking outside the box. I guess the biggest thing to remember is DON'T PANIC - just use a little ingenuity.
COOKING OIL - keep the renderings of any meat that you cook. Keep fat from beef, pork, bacon, etc. It can be used in place of cooking oil. It also can add flavor. I for one have a couple jars of bacon grease in my frig at any given time! I also keep grease from ground beef.
Butter, Crisco, lard are options as well.
For baking - you could use these if making something savory - but think about substituting applesauce, smashed bananas, or any blended smooth fruit. Sour cream could be added (cottage cheese blended up smooth as well).
SOAP - just remember - soap is soap. Some is stronger than others - but it all cleans. Bath, hair, dish, laundry - can be interchangeable if necessary. I always have bars and more bars of soap - for just in case.
Add baking soda to laundry to help clean. Peroxide is what I use instead of bleach ALWAYS - it is natural.
If you are out of dish or laundry soap - good old hot water and vinegar will work.
PASTA and RICE interchangeable in most recipes. Both easy to keep in the pantry and last for ages.
BREAD - make biscuits, tortillas, corn bread, Naan bread, etc.
STOCK - dry bouillon should always be kept on hand. Add cream of soups ( or any soups). Tomato sauce, tomato paste, salsa, spaghetti sauce, etc. added to a soup or casserole. Tomato powder is great for flavoring. Make vegetable stock - keep the water from cooking veggies. Add onion or onion powder, garlic powder. Herbs for seasoning. Blend up veggies and add with water for flavoring. Gravy mixes.
There are so many options.
MEAT - use less. Use half of what you would normally use to stretch it. Have some meatless dinners - it won't hurt you and will probably be good for you. Substitute beans for meat or some of the meat in dishes (I always add beans to taco meat to stretch). Keep protein powders on hand. Peanut butter is great source of protein. All types of beans and lentils. (You can even make burgers from these).
FRUIT - you don't have to have fresh. Canned and frozen will work fine. Frozen is actually picked ripe and flash frozen - so it is probably better for you than fresh. Fresh is generally picked before it should be.
PAPER TOWELS - cloth napkins, dish towels, wash cloths, rags. Washable and re-useable.
EGGS - keep powdered egg product on hand. Freeze eggs when you have planty. Tofu. When baking consider substituting 1/2 banana or 1/4 C applesauce for 1 egg.
CLEANING - SOAP!!!!!!! I don't buy many cleaning supplies as I like to use more natural things I have on hand. Vinegar, peroxide, baking soda, salt, even ammonia or bleach. I always have a can or two of cleanser on hand (for tough scrubs). I have had the cleanser for probably years!!!!! But I have it if needed.
Just a reminder - DO NOT MIX any chemical cleaners! They create toxic fumes and can be deadly.
DRINKS - tea - it can be flavored with juice or Kool-Aid for a different flavor. Fruit juices, coffee (hot or cold) and good old water!!!!! I keep seeing people stocking up all these bottles of water and think to myself - "I have this MAGIC gadget in my kitchen that produces water. Turn a lever and boom - water!" LOL
Water can be turned into flavored water as well.
TP - Kleenex, wipes, material from old clothing (cut into smaller pieces), used fabric softener sheets, and my favorite go to (if the need would arise) a wash cloth and soap and water!!!!!!!
SANITIZER - alcohol, witch hazel, vinegar, mouth wash, peroxide and soap and water. Bleach water can be made - but be careful. 1 part bleach to 99 parts water.
So there you have a few ideas on what you can do when the pantry is running low. Use what you have. Experiment a little - you may have a new recipe from now on! Do some research and learn to go with the flow.
Just remember - this too shall pass. DON'T panic. We got this.
Give one another comfort and encouragement - not fear and stress.
Blessings my friends.
Add any ideas you have!