There's a right way and a lazy-bum way to sew on a button.
This is a brilliant and easy Threadbanger video showing the right way to sew on a button.
And you get cool music in the background. Which makes it a kind of button-sewing-music-video.
And because this is so short and to the point, here's a little extra for you: How to organize those little zip lock bags with the extra button that comes with a new garment.