The first thing to do is to figure out how the button will look and feel.
You want it to have a soft feel, a bit of springiness, and a lot of life.
This means that it should feel like you’re pulling it out of the pocket of a shirt or sweater, not from a purse.
You also want to be able to adjust the width of the button so it will fit comfortably in your hand.
It’s all about balancing the need for visual appeal with the comfort that comes with wearing a button.