Over Christmas, one of the things I did was repair the worn-out soles of a pair of DH's socks. These were alpaca socks that I knitted for him in 2009 and, I've just realised, I've never documented. (The closest I've got was in this post, when I ended up knitting on them in a traffic jam.) The yarn is UK Alpaca's Alpaca Sock Yarn, a 60% alpaca, 20% merino wool, 20% nylon yarn.
Anyway, last winter, DH wore the ball of one foot down to the nylon.
I don't darn socks, but after the labour-of-love it took to make them, I decided I had to do something. So I hit upon the idea of knitting a patch over the top. (The rest of the socks are in good condition.) Using a latch hook, I picked up stitches along one side of the worn section and slipped them over a DPN.
Then I knitted a row and purled back. On the next and subsequent knit rows, I picked up the stitch that was parallel to the patch and knitted it together with the end stitch from the patch. (Not sure how clearly you can see that from this photo.)
Basically, I knitted a pocket that was attached across the bottom and down both sides.
When I was satisfied that the patch covered the worn area, I Kitchener stitched the patch to the sole.
Finally, I wove in the ends, using them to invisibly tack the nylon to the patch.
And voila! Not invisible - the yarn is from a different dye lot for a start - but it's soft, doesn't rub and will last for a long time.