I've sewn a few buttons on my work pants, for some reason the pants shrink until the button pops off then I have to sew it on.
But when it came to sewing on cub scout patches I just couldn't do it in a timely manor. I ended up paying the alteration station near work to do them since we had to alter the smallest shirt to shrink it down to my son's size anyway. I now have the most expensive cub scout shirt ever.