For the cabled headband, my preferred method of joining it in the round is with the Kitchener (also called grafting or weaving) stitch, because it creates an invisible join and does not add bulk. When grafting knitted pieces that are "in pattern", such as this garter, purl and knit stitch pattern, a combination of the two basic grafting stitches is used. Read more ... for quality control tips and additional information.
The photo shows the cabled headband in process, after blocking, before joining in the round, since it is easier to photograph this way. This is the fourth cabled headband I've knitted, but the first in two colors. The single color headbands take me one evening and the two color, two evenings to complete. The pattern is easy to memorize. Read more .... for tips on working the headband in two colors.