Here I have filled out the smaller petals on the left:
Here I have done some fine tuning on the same petals. A pale glaze of yellow on some inner petals makes them spring upward, leaving the other yellow petals as there keeps them a layer behind the first ones. The violet ones form another layer behind these two and adding a glaze of the shadow mix to some keeps them at the farthest plane. So you get the spatial perspective and the petals don`t look as if they have been placed next to each other.
Strengthened the shadows on the lower sunlit petal:
Watercolor Journal 