Short rows move back and forth across a subset of the stitches being worked. There's a discontinuity between the short row fabric and the main fabric. The goal of a short row technique is to bridge this discontinuity without leaving either a hole or an unsightly bump.
Everyone has their own short row method. There's the common wrap method, which works well enough in its place, but is difficult to work invisibly. There are a bunch of no-wrap techniques. Most of them accomplish the same thing, but they do them in different ways.
I started doing short rows with wraps, soon came to hate working the wraps passionately, and then tried every no-wrap technique I could find before settling on the one I use. I unvented this technique myself, but it's so obvious that I'm sure other knitters unvented it before me. I like it because it works well with every pattern stitch I've tried and because it makes my short rows almost completely invisible.
If you look closely, you can see the pick-ups in the fabric.
Short rows are always worked on either increasing or decreasing numbers of stitches. If they always ended at the same place, you'd have a huge gap that you'd never be able to bridge. The desired shape of the fabric usually dictates whether you need to do increasing or decreasing short rows, but there are times (like with bust darts) where you can choose whichever you prefer to work.
If you're doing increasing short rows, you do the pick-ups as you work past the turnaround stitches the next time you encounter them. If you're doing decreasing short rows, you work all the pick-ups after you've finished working the short rows.
Short rows increase length over the section they're worked. So, to figure how many short rows you need, you need to know how many extra rows you need to get the extra length you need.
In my method, knitting the short row is easy: I work all stitches including the turnaround stitch, then turn around, slip the turnaround stitch, and continue.
On the pick-up, I go to the spot between the turnaround stitch and the main garment and do either a left or right make-one. If I'm working before the turnaround stitch, I scoop the make-one from behind. If I'm working beyond the turnaround stitch, I scoop the make-one from the front.
Note that I scoop the make-ones with the right needle and then slip them, twisted, onto the left needle. Since the make-ones will be worked together with the turnaround stitch, this works better for me than scooping them with the left needle and twisting them when I work them.
Then I decrease the make-one with the turnaround stitch in the way that puts the turnaround stitch on top and angles it towards the short rows. On knit rows, this will be either a k2-tog or a ssk. On purl rows, this will be either a p2-tog or a p2-tog-tbl variation.
Both of these examples show me picking up the turnarounds from the right side of the fabric. This is one of the luxuries with working stockinette in the round with decreasing short rows: you never have to pick anything up from the wrong side.
The type of make-one used in closing up the short rows is not nearly as important as doing the right decrease. Unfortunately, the decrease changes depending on whether you're working it from the right or wrong side of the fabric, and whether the turnaround stitch is before or after the make-one. I had to fiddle with this for a long time before I figured it out. It's not that hard to figure out if you remember these three things:
- From the right side, the turnaround stitch needs to sit on top of the make-one. If you look at ssk and k2-tog, you'll notice that one puts the first stitch on top and the other puts the second stitch on top. Use the one that puts the turnaround on top.
- The turnaround stitch needs to be knit straight, not twisted.
- The right side needs to be a knit or purl according to the stitch pattern.
If I'm working from the wrong side, I usually turn my work around and work the pick-up from the right side so I can see what I'm doing.
There's a simpler way to do the decreases, but it involves passing the turnaround stitch over the knitted or purled make-on, so I don't think it looks quite as smooth.
Before you knit the turnaround stitch on the pick-up row, scoop the make-one. Slip the turnaround stitch first if necessary (with the yarn on the wrong side) to get it out of the way. Knit or purl the make-one in pattern, then slip it to the needle with the turnaround stitch, and pass the turnaround stitch over it.
Instead of figuring out which kind of decrease to do here, you've separated the decreases into two steps: knitting or purling the wrap or make-one and passing the turnaround stitch over that stitch. The only thing that you need to do is to make sure that the turnaround stitch is oriented the right way on the needle so it won't twist.
If you look at the item from the front, the turnaround stitches on the right-hand side (your right hand) will be oriented normally. The leading leg of the stitch will be on the front side of the needle. On the left-hand side, the stitches will need to be slipped knitwise so that the leading leg of the stitch is behind the needle.
You can examine each stitch after you pass it over the wrap or make-one. If it's twisted, pick it back up right then, untwist it, and redo it so it won't twist.