I sympathise with those who have very little/no freezer space.
I'd be lost without my freezers - 1 in house(small,fridge size) and 1 in garage (smallish fridge/freezer size).
Lockdown restrictions led to shopping changes here and experiments with what can and can't be frozen.
We eat very little sliced bread but when loaf bought, on day of purchase, I split it and freeze in 2 - 3 sliced portions. Once frozen, it can be tucked into various nooks and crannies in freezer, rather than sitting there, like a breeze block taking up the whole shelf.
Mushrooms - I cook the whole punnet(s) in a bit of butter, cool, and portion out in little pots and freeze. They are a bit rubbery, but completely edible and preferable to having none at all or wasting most.
Apples - last forever - no matter what date on bag says.
Open bag on day of purchase, and put in a folded piece of kitchen roll - doing this with most fruit/veg which comes in cellophane bags or plastic punnets helps to prolong the lifespan of contents.
Change kitchen roll piece as it becomes damp from absorbed moisture. (DH is frugal, and a Scot!, so retrieves the damp, but clean, kitchen roll pieces, dries them out and uses them for polishing his car windows or cleaning mud off his shoes.)
I'm currently experimenting with freezing eggs after supermarket click and collect order substituted my 6 large egg order for a value pack of 15 Eggs!
I've cracked 6 of them into individual silicone muffin cases, fast frozen, then put in a bag to be used as needed.
Meal planning helps reduce waste.
We also have a permanent shopping list on the kitchen worktop where we can jot items down as they're used up/coming to an end, so we can replace what's needed as we go along rather than buying something "just in case" we've got none.