I know there isn't the right way for sewing a button, but for me this is definitely the best way I learn to sew a button, doesn't require any finishing knots, and have a super strong hold.
My grandma, that was a taylor, used to do this way.
>> Vote it in the "three ingredients" contest if you like it! <<
Step 1: WHAT YOU NEED
-fabric to sewn the button on;
Step 2: PLACE THE THREAD
Place the thread DOUBLE on your needle.
Step 3: MAKE a KNOT
Make a simple knot or two at the end of the thread.
It is not really necessary, but I just do it to stop the thread without pay attention.
Step 4: START
Just sew a small section of the fabric, where the button should go.
Step 5: PLACE THE BUTTON
Insert the button in the thread.
Step 6: SEW THE BUTTON
Simply sew the button to the fabric.
DO NOT SEW THE BUTTON TOO TIGH TO THE FABRIC: leave a small space between the button and the fabric, so the buttonhole will eventually be able to fit there.
Step 7: KEEP SEWING
Keep sewing the button to the fabric for 5 or 6 times, as desired.
Step 8: EXIT
Exit with the thread under the button, BUT on top of the fabric.
Step 9: WRAP
Turn the thread around the button for 4 or 5 times.
Step 10: INSERT THE THREAD
Than insert the thread between the button and the fabric, in the sewn you did.
Before in one direction, than in the other, and pull.
Step 11: CUT
Cut away the remanning thread.
You don't need any extra knots.
Step 12: DONE
This way your shirts will fell apart before your buttons!