The more professionally accepted way to finish your binding is to sew it by hand to the back of your quilt. For heirloom pieces I prefer this method, but for quick, functional quilt I use the machine sewn method. The directions are very similar, but I will list them out here separately so that the directions are clear.
Creating your binding
Measure around the entire outer edge of your quilt and then add 20 inches to this measurement.
Divide this total by 40.
This new number is the number of strips that you need to cut. If you came up with a decimal, round your number up to the next whole number. For example, if your result was 7.6, round up to 8.
To connect your strips together, make the seam on the diagonal. Lay the first strip right side up and the second strip on top with right sides together, perpendicular to the first strip. Sew on the diagonal from point to point.
Trim off the excess 1/4" from the seam line.
Repeat this until you have one continuous strip of fabric.
Press this strip in half lengthwise with wrong sides together like a long hot dog bun.
You have now prepared your binding to be attached to your quilt!
Attaching your binding (Directions for hand sewing your binding)
Start in the middle of one side of your quilt. Align the raw edges of your binding with the raw edges of the front of your quilt sandwich. Stitch with a ¼” seam allowance. Leave a long tail of about 10” before you begin stitching your binding down to help you later.
When you get to a corner, stop your stitching ¼” before you get to the edge of the quilt.
Remove quilt from the machine.
Lay the binding out so that it extends straight beyond the quilt edge.
Fold the binding up so that it creates a 45 degree angle at the corner and the raw edges of the binding extend upward from the quilt and remain in line with the next edge of the quilt to be bound.
Fold the binding back down on to the quilt. The fold of the binding should match up with the top edge of the quilt and the raw edges should come back down to once again align with the raw edges of the quilt.
Begin stiching again at the corner.
Repeat these steps for each corner.
Once you get back to the side in which you started your binding, stop stitching approximately 10 “ from the beginning stitch and leave a long tail free from the quilt once again.
Connecting your binding
Lay the first tail down across the gap and cut the tail off so that it ends in approximately the middle of the gap.
Lay the second tail down on top of the first tail. You want the tails to overlap each other a total of 2.5”. Using your ruler or a hem guide, align the end of your measuring device with the end of the first tail and cut the second tail at the 2.5” mark.
Open the other tail and angle it off the quilt top to lay it right sides together at an angle with the first tail. This will be a tight fit and you will need to fold in the left side of the quilt to help give you enough room to get these two pieces aligned. Pin.
Sew on the diagonal from point to point.
Straighten out the quilt edge and make sure that your binding is going to lay down nicely over the gap.
If your seam was done correctly, pull the binding back out and trim the excess ¼” away from the diagonal seam.
Finishing your Binding
Turn your quilt over to the back side and pull the binding around to the back.
Starting at one corner, overlap the folded edge of the binding with the straight stitching line that is securing it to the back and pin.
Using a doubled strand of thread, secure the knot behind your binding at the corner.
You'll want to use a blind hem stitch to secure your binding to the backing. To do this, have your needle come out of the binding at the folded edge, and enter the backing directly across from where it exited the binding.
Once that stitch is taken, have the needle enter the edge of the binding directly across from where it left the backing.
By placing the starts and stops of your stitches directly across from each other you will keep them hidden from sight. A BLIND hem stitch!
When you get to a corner, keep the folded edge of the binding going straight beyond the quilt edge to the folded edge of the binding on the next side. A natural 45 degree angle will occur on the outer edge of the binding. Just like in the previous pictures. Fold the next edge up, matching the next binding edge with the straight line of stitching that is securing the binding. You should now have a 45 degree angle at the corner of your binding.
Repeat this for each corner continue to use your blind hem stitch around the entire edge of the quilt.
Fold the lower edge up and match the point with the edge of the first side of the binding and allow the edge of the binding to once again cover the straight line of stitching that is securing the binding strip.
Repeat this for each corner.
When you get back to your starting stitch, take a couple back stitches to secure the binding at the end and you’re done!