This is one of my favourite methods to cast off when I am looking for something with a little more pizzazz! It is actually a lot simpler than it looks.
When you are ready to cast off, either with the right or wrong side of your working facing you (I prefer the wrong side facing as I find it gives a neater finish), follow the following steps:
Cast off the first stitch as usual, then in the next stitch, cast on two stitches by beginning to knit the next stitch but leave the loop of the stitch on the left needle and slip the loop created on the right needle back onto to the left needle.
Follow the same step as above in the stitch just created so that you now have three stitches.
Cast off 4 stitches, this will cast off the two stitches just created, plus the original stitch and one additional stitch.
This creates a small knob on the cast off edge.
Continue repeating these steps across the row; cast on 2, cast off 4, until you reach the end of the row. Don’t worry if you have a stitch left over at the end of the row, just cast off this stitch as usual.
Many variations of this stitch can be accomplished by changing the number of stitches cast on and off. The purple sample was created by casting on 1 stitch and casting off 6, and the pink was created by casting on 3 stitches and casting off 5.
Even changing whether you cast off with the wrong side or the right side facing changes the look slightly. The green sample above was cast off with the wrong side facing and the red with the right side facing.
I hope you enjoy experimenting with this technique!