You are all going to think that I just like expensive things. That's not true ... exactly. What I like is quality stuff - stuff that lasts - and what I've found is that there is absolute truth to the saying, "You get what you pay for." If one buys cheap stuff, that's what one gets.
My favorite socks are 100% (or as close to 100 as I can get) Merino wool socks. They're expensive, but they are warm, and while they don't last, they are amazing foot covers on cold, winter days in Maine, because they keep my feet not only warm, but also dry - which is actually a pretty important part of the whole staying "warm" thing.
So, when the dogs come in the house, tracking snow down the hallways and all over, which leaves little puddles all over the place, which, of course, I step in, my feet don't get wet. The wool just wicks that wet and keeps it away from my skin, and those socks dry really fast, even on my feet, in the desert-dry air of my wood-heated house.
Merino wool socks cost a lot of money. I can wear a pair for about a season before the hole is too big to keep wearing them.
After a couple of years of buying three or so new pairs every season, I had a drawer-full of holey socks, and I figured it was time I did something about it.
I learned to darn.
It's actually quite easy. My first attempts weren't actual darning, at all. Basically, using an embroidery needle and some yarn, I sewed a patch. I started by sewing around the edge of the hole, and then, working my way around the hole, I added layers until the hole was completely filled in. It worked, mostly.
Then, I watched a video on YouTube about how to actually darn a sock. Basically, it's a weaving process. Sew across the hole in one direction, and then, from the other direction, weave the yarn through the first cross.
Et viola! A fixed sock.
I could, probably, find a yarn that more closely matches the original sock color ... but then, how would anyone be able to admire my skill and frugality?
P.S. I don't own a darning "mushroom". I actually use an orange. I used to use a plastic Poke-Ball, but I've since lost it. Anything round will work.