I made one, as part of a female creature, a long time ago.  If I remember correctly, what I did was make the petals individually and then arrange them into the flower's shape.  I believe I started at the center, and worked my way outwards, increasing the size of the petals as I went.

Here it is if you want to look (warning: contains nudity):

http://www.angelfire.com/ult/ace/blue_venus_weed.html