Things You'll Need
Add an edging to a blanket or other square knit item by knitting around the corners. The corners need increases in order to lay flat at the edge of the blanket. You can use a long circular needle to work the entire edging of the blanket or piece all at once. There are a few different ways to work the increases, so pick the one that gives you the look you want for the corners.
Pick up and knit along the edge of the piece by slipping one needle into the stitch at the edge, wrapping the yarn around the stitch counterclockwise and pulling the new loop of yarn through the edge stitch.
Pick up and knit to the corner, place a marker, pick up and knit one stitch at the corner and place another marker after that stitch. Repeat for all four corners.
Work in your chosen edge stitch to the marker. Slip the marker, increase one stitch, work to the next marker, increase one stitch then slip the marker. Repeat around the blanket.
Use the right-hand needle to pull up the bar of yarn between the stitch just worked and the next stitch on the left-hand needle for a make one increase. Place the stitch on the left-hand needle. Knit or purl into the back of the stitch. Repeat for all increases.
Pass the yarn over the needle from the back to the front for a knit stitch or from the front to the back for a purl stitch for a yarn over increase. Work the next stitch normally. Repeat for all increases.
Continue working in this manner, increasing after the first marker at each corner and before the second marker at each corner on every other row, each right side row, until the border is the desired length.