Another thing: Several years ago I invested 20 quid in a set of glass storage containers with fitted lids.
Since then I have not purchased tin foil or plastic bags. I use the glass containers (or even washed, empty jars from food purchases) to store leftovers or other items in the fridge. It's a bit more faff but where there is a will, there's a way, and it makes me feel good not to use up and throw away the planet's resources.
I do keep a roll of parchment paper on hand and use it very sparingly; mainly when the mess would use lots of water, such as when cooking a lot of bacon in the oven. Have lots of old beat-up tea towels so rarely use kitchen roll.
A jar of coconut oil can suffice for everything from face creme and hair conditioner to oil for squeaky doors to furniture polish. It doesn't go rancid so is a very good multi-purpose oil to have on hand, rather than buying an area of products from WD40 to makeup remover.
Cut out a lot of carbs like bagels, cakes, breads, biscuits, etc.; we have one loaf of whole-grain bread on hand and that has to do for sandwiches, accompaniment to spaghetti, a "roll" for a burger or whatnot. No more throwing away stale breads or finding them spoiled in the freezer.
Mushrooms make a "meaty" substitute or beef, pork and poultry. With a jacket potato and a salad, quite filling.
Same for olives; one of our favorite light meals is a sort of open cheese toastie made by heaping chopped or sliced green (stuffed) olives beneath the cheese before putting under the grill (sans a top piece of bread) until the cheese bubbles; it's a hearty meal with soup, salad or crudite.