I refused to toss out the marvelous LL Bean's Ragg wool socks we wore on our back packing honeymoon...in 1967. His wore out, mine I'm still wearing in winters with felt soles sewed under for foot pads. Warm and comfy in the evening. Have one pair still left in fair condition, about time to toss the other pair and put on another felt padding on these.
Wash clothes in cold water, same result as hot so save money that way. Put quilt batting and muslin behind all drapes, sure does help with the power bills. And I made rolls of batting rolled over a long bag of sand and sewn into fabric for draft dodgers. Sure does help with cold floors.
Put bubble wrap on windows where the drapes are never opened, which usually means on the North side of the house and on a pair of hideously hot South facing ones.
Make lists for shopping days, with shops planned in a smooth curve and no back tracking. That irritates me as well as wastes
gas. And shop with lists, with Costco last and have lunch there.
I love their hot dogs, don't plan to give them up. A big Hot dog and refillable soda still $1.50.
Big savings is in books, I read fast and go thorough massive amounts of them every month. So I shop yard sales, flea markets, library used book store (I donate them back after reading) and graciously accept all donations. The library itself doesn't have many new ones these days of money cuts, but they still have masses of other, older ones I haven't read yet.
And to save most of all, I've learned to make many repairs to the house that when first married I never thought I'd ever have to.