Place your stitches on circular needles or double-pointed needles. If using double-pointed needles, distribute them evenly (shown here on 3, but you can use 4 if you prefer). Note: Before you join, make sure your yarn is in the back of the work if you are starting with a knit stitch. If you are starting with a purl, place your yarn in the front. You will not be able to move the yarn after joining.
Place the first stitch from the right needle onto the left needle (Stitch A).
Pull the first stitch from the left needle (Stitch B) over Stitch A onto the right needle. Your knitting will now be joined in the round. Stitch A will the the first stitch of the round. Stitch B will the last stitch of the round. Knit normally into the first stitch.