I tried my hand at darning socks today. I would say the results are mediocre but that has more to do with a lack of finesse in my technique than anything. I found a great video on how to do it and pulled out my holey socks.
The sock on the left had an actual hole in the heel and I darned it according to the video instructions. I have a small darning mushroom that I received as a gift that I got to use for the first time. If the hole had been any bigger I think an actual darning egg would have been a better choice.
The sock on the right was just threadbare in the heel and about to explode. Instead of waiting for a sock emergency I duplicate stitched over the patch that looked ready to fall apart. I like the look of it better than the darning and if I notice a sock ready to give out I think I'd rather implement the duplicate stitch method of sock-saving. I'm glad I was able to repair these socks, learn a new technique, and add some knitwear back into my rotation.