Make four small swatches using smooth, light colored yarn. It is easiest to see with worsted weight yarn, but any weight yarn and appropriate needles will work. Wet block them so the edges lay flat.
Swatches 1 and 2:
Cast on 6 stitches, leaving a 10″ tail. Work 16 rows in stockinette stitch, then work 16 rows in garter stitch. On these swatches DO NOT slip the selvedge stitches. Bind off, leaving a 10″ tail for seaming.
Swatches 3 and 4:
Cast on 10 sts and work 10 rows of stockinette stitch. DO NOT bind off these swatches but leave each on a needle. We will join the live stitches wth 3-needle bind-off, then crochet the selvedges together.
Bring with you:
Yarn for seaming, the same as your swatches or a similar yarn of a different color
Darning or tapetry needle.
Another knitting needle of the size used for your swatches
Crochet hook of appropriate size for your swatch yarn. (Size H is good with worsted weight yarn.)