How do I Make Flower Buttonholes?

I recently turned a white cardigan sweater into the prettiest creation with flower button holes. I bought two stems of silk daisies and pulled them off the stems. I pulled out the center of the daisy and sewed it onto the sweater around the button hole. Now the center of the daisy is my button hole. I went a step further and replaced the white buttons with yellow ones which now makes the center of my daisies yellow when my sweater is buttoned.