Thrift stores out of season. Look for your winter jacket in June, you'll get the nicer brands, and most thrift stores will do some kind of rotating discount on certain colored tags. Most 'dry clean only' items can indeed be machine washed on gentle.
Preserved and frozen meats and fish can be made into fantastic recipes. We do salsa chicken straight from frozen in the instant pot, and I make a killer pasta with tinned sardines and breadcrumbs. The benefit of these is that you can buy them on sale and don't have to worry about cooking them quickly to avoid spoiling.
Drugstore makeup can be just as good as expensive stuff. Aldi moisturizers are incredible and $4 a pot. I splash out on super expensive shampoo and conditioner, so I don't have reccs there, but my husband swears by Aldi's black and white bottle stuff.
And this tip is a little wild, but learning to forage can be immense. There is so much free edible food around you, from flowers and leaves that make delicious tea (passiflora flowers), weeds that can substitute salad greens (lambs quarters, kudzu, and wood sorrel), to absolutely delicious fruit that you couldn't even buy if you wanted to (pawpaws!). Use the golden rules of having three different ways to identify it (three sources, don't just use photo ID apps, learn the description, not just the visuals) and also know the sickly lookalikes, and never forage for carrots or parsley.
You can straight up live off oyster mushrooms for like 2-3 months in a cold season. And the mighty little “potato bean” Apios americana, grows in almost every slightly moist disturbed area and is much more nutritious than potatoes. (Louisiana)