1) First mark your intended cut lines - in this case follow a circular/spiral pattern. All cutting should be done with something like a pumpkin carver.
2) Make a floral pattern cutting out small circles resembling the center of a flower and its separate petals.
3) Cut larger "petals" around the edge of the interior petals.
4) Continue this pattern, making larger petals with each expansion.
5) As you get further to the outside, adopt "leaf-like" cuts - more angular or triangular to give the appearance of a a flower sitting on a bed of leaves.