Use a spare needle and one of your main needles. Holding two needles parallel make a slip knot over both ends, pull tight. Hold a length of waste yarn underneath the working yarn. * Move the working yarn in front of the waste yarn, wrap it underneath then bring it over the needles from front to back. *
Rep from * to * until you have cast on the desired number of stitches. You should have the same number of stitches on the needle as the wraps around the waste yarn.
Keeping the two cast on needles in place, knit the first row. Now remove one or both of the cast on needles and begin to knit. After a few rows, remove the last needle. The cast on stitches will remain larger than the other stitches. Keep knitting until you have finished the necessary section.
To pick up the cast on stitches, insert your needle through the loops and remove the waste yarn. Give the needle a few gentle tugs to even out the stitches then begin knitting in the opposite direction.