I like to make the most of my sock yarn, even when there are only a few grammes left, and after seeing the grumperina knit stripey socks a while ago, I have developed her technique for my own ends to make simply stripey socks. This is how I do it:
1. Have a good rummage in the stash, and choose some sock yarns in complementary colours/shades.
2. Weigh the yarn and make sure there is enough to make a pair of socks. (I know that I need at least 50g to make a pair of plain vanilla socks in my size). If there isn't, then go back to step one and rummage some more.
2. Divide any small balls into two roughly equal portions.
3. Cast on in the usual way and knit the sock cuff using one of the yarns. In this instance, because there is a lot of green and not much of the others, then I am using the green as the 'main' colour.
4. When the cuff is the required length, start on the leg of the sock. Introduce your additional yarns/colours at this point.
A. If there are only two colours/yarns, then work the first round in the new colour and then go back to the main colour for the second round, then revert to the new colour for round three. Continue knitting in this way, alternating colours/yarns until the leg of your sock is the required length.
Joining the second yarn after the cuff
B. If you have three colours/yarns to work with (as I have here), then join the first colour at the beginning of the round, AND then join the second colour the next time you change needles. Continue knitting in that colour until you encounter the main colour again (at the end of the round). Pick this up and knit until you meet the tail of the first colour and then knit with that one.
If you find yourself with all of your yarn tails at the same point, all you need to remember is to ALWAYS knit with the LOWEST yarn available. In the picture below, this means taking the paler green yarn (on the left).
I find knitting these stripes really addictive, and once I've started it's hard to stop - although I do break from time to time to admire the effect. One of the yarns I'm using here is a self-striping one, changing from cream to green and back again.
Keep knitting until the leg is the desired length and prepare for the heel flap. I knit this in one colour - in this case, the same colour as the cuff, so I make sure that the yarns are in the right place. The spare yarns should be 'parked' just before the heel flap, as shown below.
Heel flap and yarn on left (front) needle; spare yarns parked on right (back)needle.
Continue knitting the heel flap in the normal way until you start to pick up the stitches along the side of the flap. You should find that as you come to pick up stitches on the second side of the heel flap that you encounter your spare yarns again. As always, work with the lowest yarn available and use this to pick up the stitches on the second side of the heel flap.