Just came back from an exceptionally cold vacation to Iceland and realized that despite years of backpacking and hiking in temperate weather, I knew not nearly enough about layering for truly cold weather.
I mostly bought them to keep my dry, rather than warmer.
Which ones?
I second this. My wife went through a health scare (she's fine now) early in 2022, during which she was a little depressed. one of her outlets was to go to home goods or lowes and buy house plants - one or two at a time, every week or two. those stores have pretty generous return policies if you kill the plant - homegoods 30 days, lowes - a full year!
I think we have about 25 houseplants now including a couple of large ficus and fan palm trees, she waters them all at once on the weekend and it doesn't take much time at all, maybe 15 to 30 minutes per week; there are some annual maintenance tasks as well like re-potting but the return on time investment is really fantastic. Guests always comment how lovely it is in our living room surrounded by plants, and she has a new hobby of propagating the houseplants and giving new plants as gifts. All in all, I'm sure it's more than $200 in total, but if you find good deals, $200 can probably buy between 5 to 15 very nice houseplants.
I bought some new plants for my home, which makes the place feel a lot nicer.
I bought some outdoor-trousers - things that go on top of your jeans - when it is cold they keep me warm, and I can now roll around in the snow without getting wet as a nice bonus. (-10°C here today). That said it was only a couple of weeks ago that I came out of a sauna and rolled around naked in 30cm of snow. Bracing!
Other household things that have made my life nicer have included some decent concrete-bolts screwed into my walls and ceiling. Now I can hang plants, have an indoor hammock, and a hammock-chair too.
Finally I've started buying random paintings whenever I go to visit charity/thrift stores. Each time I go I buy a single painting, it must be "amateur", and it must have an artist signature and date on it. At the moment I've got a wall with about eight of these paintings hung on it. All different styles, colours, and levels of "goodness", but together they all look good, rather than a garish mismash. Kinda fun.