I sew buttons on by machine, drop your feed dog, change your zigzag to the width of the holes, I think it is 3 to 3.5,(All but the tiny tiny buttons have the same hole width) (if you can't drop your feed dogs, change your stitch length to 0) stick everything under the presser foot (some machines have a specific food but you don't need it) and do the first stitches by turning the wheel to make sure that the needle will go in both holes, and then just step on it, if the button is in the wrong position you run a risk of breaking the needle and or button.