I had always tried to reduce my food waste and we have composted all of our fruit/veggie scraps and coffee grounds for as long as I remember, but right up until I retired, I still had some stuff get away from me and have to toss out food that had gone bad. Not often, but it pained me when I forgot to use up something like that. But since I've retired, I have almost zero food waste because I'm more on top of what is in the fridge and what is borderline, and use it up or chop/freeze to avoid items going bad.
I don't peel potatoes or carrots (eat the peels! Mashed potatoes are still tasty with the skins in there!), I save the ends of celery and carrots and such for stock (baggie in the freezer). I throw fruit in the freezer if we can't eat them all before going overripe and we use them for smoothies.
I grew up with a father that laughed at expiration dates and I always look for dented or clearance sections in the store and buy that stuff if I can use it, so I'd like to think I'm keeping some of that out of the garbage as well saving a ton of money. I had a great score recently with dented cans of pumpkin, crushed tomatoes and pasta (the bags were had some cut marks from unboxing, otherwise fine!). As long as the can goods aren't crushed to break the seal, they're still good and I got them for pennies!
I had a bad experience with spoiled milk as a kid (father insisted I drink the "funny tasting" milk, got angry at me when I wouldn't drink all of it, and then finally tasted it himself and realized it had spoiled) so my husband is the official "has it gone off yet?" checker for that, otherwise I'm fine with testing foods/drinks myself. But in general we hardly ever have anything get to that point as I'm also better positioned to plan out our meals and shop accordingly so there's little food coming into the house that isn't used up well before its time.
I like fresh fruits and veggies, but I buy more frozen as I've read that in many cases the frozen stuff might have better nutrient content than the "fresh" fruits and veggies that took weeks to get to the supermarket, and I can keep frozen goods way longer than fresh.
What about the grocery stores that specialize in expired food? I know there are some around my area, and I need to figure out where they are, but I don't understand why more regular stores don't sell their close to expired/past the sell by date stuff instead of throwing it out.