You've done it! All this was done on a basic sewing machine at TechShop.
I'm pretty lazy, especially when it comes to handsewing buttons. Luckily I can do them by machine! Some sewing machines have a special button you can press that automatically inputs all the settings you need to do buttons, but not everyone has one of those fancy-pants machines. Following these instructions you can do this on any machine that can do a zigzag stitch!
Step 1: Choosing Buttons
This method will only work with buttons that have holes all the way through from top to bottom. It will work with either two holes or four; you'll simply sew one pair of holes at a time. It will NOT work on buttons that have a shank. See photo for examples of each.