The stitch seems very forgiving of variation, so it works well, and shawls don't really have to fit. I've seen it called double moss stitch, garter rib and other names I can't recall. It looks like garter stitch, but it doesn't seem to sag like garter, and it breaks up that unflattering horizontal stripe ;-).
The shawl is very 'stoneground wholemeal' to borrow a phrase from a friend. It may or may not suit your public life, but it's very useful and cuddly for around the house. It also magically heals sick kids ;-).
If you use commercial yarn, use a single ply chunky or bulky with a thinner strand of something soft and shiny. Handspun mohair isn't usually like commercial mohair - it's smooth with a lovely sheen, and gently 'blooms' as you use the garment.
Materials:
About a kilo (2.2 lb) of easy to spin roving. I used white.
About 300g (11oz) kid mohair, preferably tops or roving (this stuff
flies everywhere when you try to comb it, but it is So Gorgeous). I used
white here too; I liked the subtlety of it.
The longest circular needle you can find in a suitable size. I think
I used a 6mm.
Spinning Instructions:
Fill all but two of your bobbins with loosely twisted singles. Thick slubs are fine, thin patches are fine, just try not to have long stretches of either. Don't stress out if you have overtwisted bits - the softer parts will compensate. You want to spin as much as possible now because you won't be able to make more of this lumpy yarn later, and you'll find it hard to finish your shawl.
Remember - you can never have enough bobbins, no matter how skilled a spinner you are. You should always try to spin up the yarn for a project all at one time, to keep it as consistent as possible.
Fill one bobbin with a finer single of the mohair. After all the other spinning, you should have a lot more control. This doesn't need to be lumpy.
Ply your wool single with the mohair single.
Spin more wool and mohair.
Once you've got enough, you can start knitting.
The pattern:
Cast on four stitches.
Row 1: K2, P2.
Every other row: K the P stitches, P the K stitches AS THEY FACE YOU.
At the same time - at the beginning of each row, work the first stitch in pattern, then YO.
Keep going until it's big enough, you run out of yarn, you can't fit any more stitches on the needle, or whatever :-).
The shawl has a row of 'holes' - the YOs - along the two diagonal sides. You can make a fringe, crochet an edging, or just leave them as they are. It's your shawl - and your handspun. Make it how _you_ like. You can even dye it if you like - just remember the mohair takes acid dye more than wool does, so the will stand out more.
Note:
Lay all your handspun balls out. Alternate the chunkier ones with the
thinner ones, and knit the balls in that order. If your yarn gets too fine
so that it leaves big patches, either use two strands or alternate
rows with two balls, one thick and one thin.