When I first learned to quilt, I was taught to attach binding by machine, then fold it over and finish it by hand. But that took way too long. I had quilts piling up, all finished except the binding would only be partially done because I'm not much of a hand sewer. Then I figured out how to attach binding completely by machine--yay, problem solved!
Let's get sewing:
I like to start about 1/3 of the way down on the right side of the quilt.
Open the binding end that you cut into a point in the last step of my first binding tutorial. Pin about six inches of the bottom layer of the binding to the quilt top, lining up the raw edge with the quilt top edge.
Sew only the bottom layer for the first 6 inches, using a 1/4" seam allowance.
Align both binding edges with the edge of the quilt top and pin along the remainder of the first side. Place the last pin 1/4" from the quilt top edge.
Begin sewing where you ended the last seam--about 6" from the start of the binding. (The yellow pin in the above picture is where I started sewing.) Sew along the side until there is 1/4" to the quilt top edge--I sewed until the red pin in the pic below, then backstitched and cut my thread.
You can see in the picture below that I left 1/4" free after my seam. That's important, otherwise your corner won't be nice and mitered.
Fold binding up at a 90 degree angle to your first seam. It should make a diagonal:
Then, fold the binding down, trapping the diagonal that you just made. Pin binding along the whole side, making sure to start and stop 1/4" the from the quilt edge. Sew between the pins. Repeat this until you've attached binding to all four sides.
When you get to where you started, overlap several inches and cut off any extra binding.
Fold over the top layer of your starting end, encasing the raw edge at the end of the binding. Sew over both binding ends.
Lay your quilt out flat and smooth. Carefully trim off the extra batting and backing. Cut along the raw edges of the quilt top and binding.
Fold over the binding to the back of the quilt and pin. Make sure to hide the seam where you attached the binding to the front. At the corners, fold one side on top of the other to make an attractive corner.
Sew 1/8" from the folded edge of the binding, all around the perimeter of the quilt.
Here's a finished corner from the back:
And that's it--now your quilt is 100% complete!