I've learned to darn socks and did a pretty good job of it - as in it looks ok and feels ok.
I noticed when I washed my socks, that the first one I made (and wore with a slipper for the other foot,
So...I Googled "darning" and found several websites that showed or told how to darn.
I started out using an egg. No, not a darning egg. I don't have one of those. I went to the fridge and got...an egg. Worked pretty well for the smaller areas, but I had the sole of the foot that needed major work. So...I got a burned-out lightbulb and hey, that did the trick and it has that "neck" on it that made a really good handle.
I guess I should have taken pictures, but I forgot. Again. sigh
I used a mixture of methods. On some small areas, I did a "swiss darn" aka "duplicate stitching". On the larger, really thin areas, I just "rewove" the missing yarn, over and under or along side the existing stitches.
Also, since these were 100% wool, I left a short bit of wool on each end of length of wool I was darning with and didn't make any knots. I didn't want to be walking on knots or hard spots and knew the wool would felt. The darning felt weird next to my skin for the first day I wore them (worsted weight socks that I wear around the house), but then it packed down and feels fine now. I had enough yarn left over to make another pair of socks, so there was more than enough matching yarn to darn with.
If my darning hadn't worked, I was looking at just knitting another bottom for them. I've done that with a slipper-sock I knitted for my son. It didn't look pretty - most of the bottom was missing, but it's good enough for him to wear to slide around the house in and he said it didn't feel uncomfortable. But then again, it was a double-soled sock and it was the bottom sole that he wore through, with some help from a certain puppy dog who will remain unnamed.
Here are the websites I used:
I also used this technique:
And then here's a good video of how it's done. Make sure you watch to the end, they have some tips in there on what to do and also so the finished darn with a nearly matching color.
I'm sorry that I don't have live links. Today, for some reason, I can not get the hyper-links to set up correctly. Either the published blog give me a blank spot where the link should be or it won't publish at all with the html code. sigh
Happy knit repairing.