I read about making afterthought heels, where a person knits the sock with no heel, then adds it afterward once the tube shape is finished. There are some very distinct advantages to such an approach, one being that it makes for a really good stash buster, in that you can just knit up all the yarn you have, then stick a heal and toe on from some other left over. Another advantage that appeals to me is that you can knit mindlessly - I'm getting pretty good at knitting without looking, as long as it's just continuous stocking stitch. If I can just knit a tube in movie theaters and meetings, I can do the thinking parts another time. The downside of the technique is pretty obvious, though. "You want me to CUT my KNITTING????? I don't THINK SO!!!!" Something like standing on the bridge and jumping off, the vary thought goes completely against every
instinct in your being.

But, I discovered that like
bungee jumping, once you swallow hard and force yourself to jump, you realize that it's really not all that bad. In fact, it's kind of fun! When you just will yourself to make that cut, it's a similar feeling. There's something of a rush in conquering your involuntary impulses like that, and gives you a triumphant feeling of euphoria when it's over. (Okay, well, maybe I shouldn't go that far. But it is pretty cool.
So - the first photo shows how you prep for the surgery. You decide where you want the heel to go, how wide it should be (half the overall stitches is a good rule of thumb.) and slip one side of each stitch on your needles.

This photo shows a little better - you look at those little "v"s and just take one leg of each down the row. You skip a row, and do the same below. This positions your needles so that when you remove that row
in between them they are ready to start knitting the hole shut, in
essence.

It's hard to see here, but there's a row between where the needles are placed. That center stitch is what I'm cutting.

You unravel the center "sacrificial" row, and there you go! A nice opening with the needles ready to rock and roll. The little tails of the unraveled row left can be worked in when you're done, or paired with your new yarn and knitted into the heel. Your new heel can be an hourglass, a center decrease (I'm not sure I totally understand the difference between the two, but they look like the heels in store bought socks. I think the one I've made is a center decrease) or you can knit a wedge toe which functions nicely as a heel as well.
See? The thrill of
bungee jumping without messing up your hair!