Pin the pieces right sides together.
If you haven’t counted rows and one piece is slightly longer or wider than the other, you have to ease in the extra fabric so the pieces begin and end in the same place.
With a tapestry needle and yarn, bring the needle from the bottom up through both layers 1 stitch in from the edge.
Pass the needle between the strands of yarn, not through strands.
Go around the edge, come out in the same spot to secure the end of the yarn, and bring the bottom edges of the pieces together.
This step begins to form the binding stitch
Go around again and come out 1 stitch farther up from the initial stitch.
You can begin to see the way that the backstitch joins the knit pieces.
Insert the needle back through the initial stitch and bring the tip out through both layers again
Bring the tip out a few stitches from where it last came out.
Continue in this manner — going forward, coming back — and keep an even tension.
Bring your needle in and out in the spaces between stitches and avoid splitting the working yarn. Also, give your knitting a gentle stretch while you work to keep it flexible.