I do and has been my way of life for at least 20 years.
I do save jars, remove labels and use them again for storing my own jam or pickles. Today I pickled cucumber slices and put them back in a jar of pickled onions I had just finished - saving the vinegar. (slightly more complicated because I added spices and sugar/ tumeric to the mix, boiled etc ) But they're in there now, next to the 3 jars of ploughmans pickle I made last week.
I do save foil usually for covering things to keep warm, but when destroyed beyond use it gets shoved in a coke can - and crushed to be put with all the other coke cans that I save and once a year weigh them in for scrap metal.
Corned beef has fat on the outside I keep refrigerated for frying potatoes. I make stock from all chicken bones and skin. This I freeze in old plastic chinese tubs which leaves a layer of fat on the top. This is then used first to fry onions if I am making soup, then other vegetables added and finally the stock itself.
The bones are roasted, ground up and used when planting out seedlings.
We have a regular bin, recycling bin and a food waste bin collected by the council weekly. I compost all food waste so we never use the collection service, so I have turned that free bin into a worm bin. There is also another bin I use for cooked food waste that is a Bokashi bin. All eventually end up in the garden to feed vegetables that we eat.
Tea bags are dried and coffee grounds saved. Te bags are emptied and the powder used on the garden, or in the worm bin, or composted.
Potato peelings need special treatment because they harbour potato scab virus. These are baked till dry and crispy, then rough ground with a bottle, then used to make boksahi bran for the bucket. I store it with dried crushed eggshells in cracker tubs.
Honestly if you look in our oven right now it will be aluminium trays with baked eggshells, blackened bones and crispy potato skins with bunches of herbs drying over it. Anyone would think I was a witch.
For the first time this year I have been sprouting onions from their bases, spring onions, and even a cone cabbage just from the centre stalk, as well as celery and leeks. All were started in water and then potted up. I am planting them for their seed as seed is in short supply too now.
I save junk mail for the cat - as he uses it for #2's, although I have caught him using our toilet paper too. He only pees in his litter trays and I use sawdust for those so that gets composted safely. He is the only one that uses the sheets of paper on the hook in the toilet... but if shortages of toilet roll carry on we may all start using it!
My car - 1968 that is maintained by me.
My hairstyle that is maintained by me.
I make my own beer wine and cider, cordial, jams & pickles, and grow as much food as I can. Also make compost and potting soil, and now fertiliser from the worm bins and weeds.
If I need something I am more inclined to buy the machine or tool to make it or repair it myself than pay others to do it. I've just bought a meat grinder with sausage nozzles to have a go at that....It was broken when I bought it - and therefore cheap, but now working perfectly. Likewise with the kenwood chef, all the TV's I own, fridge, washing machine, lawn mower...I buy most of my stuff broken.
When I buy a new pair of trousers I add another layer of black polycotton inside in the areas they always wear out. These then become harder wearing and is a trick I picked up from military and workwear designs.
I average at one new pair a year, and one pair of boots.
I think that's pretty frugal.