The disc florets spiral out from the center in Fibonacci sequence. This pattern provides the optimal number of flowers and seeds for the given space. The pattern can be easily seen in the un-opened disc flowers at the center. My pencil sketch included the placement of the ray flower petals and the spiral lines in the center's unopened florets.
Background color was added between the petals and additional shades of yellow were used to continue to define the open disk flowers. The bee was painted. Many additional layers of color were added to develop the background, flower and bee.