I've thought of a few things.
Instead of turning on the a/c, open windows -- if it isn't too hot outside.
Use a clothesline instead of the dryer.
Unplug everything that uses electricity when not in use.
Wash everything in cold water, except towels, sheets, underwear
Use less laundry detergent that the manufacturer calls for - I've read in reputable places that they require too much.
You can make your own laundry detergent, but that is a pain in the buttinsky.
Actually eat the food you buy.
Plan car trips so all errands are run at once, to economize on gas.
Do not use Door Dash or takeout -- instead, for the days you are too tired to prepare a meal, have something already prepared in the freezer.
Stop buying organic food.
Make a menu for the week and then make the list after checking that you are out of what's on the list.
Do not skimp on your prescriptions, especially if they are life-saving drugs.
Get some exercise. If you have mobility problems, Youtube has chair yoga and resistance band videos.
Learn to meditate, and actually do it.
Use microfiber cloths or those Swedish cloths instead of paper towels.
If you have a large supply of cloth napkins, use them instead of paper napkins.
Meat has gotten real expensive, so half the amount you eat, especially in recipes like chili and spaghetti sauce. Double the beans you put in chili, for instance.
Frozen veg are cheaper and more nutritious.
If you can, keep a garden of veg you like.
Keep a sharp eye out for other people's needs. Maybe you have something they can use to solve a problem.
Do not waste money on junk food, and make what you can from scratch.