I cut the sunflower and leaf from 140 lb. watercolor paper.
They were then colored with watercolors. I use Winsor and Newton Professional Watercolor.
I used a bright yellow, Winsor Lemon, for the flower petals and Burnt Sienna for the shading.
I painted the petals solid yellow and while the petals were still wet, I wiped back the highlights with a damp brush.
I applied the Burnt Sienna to the base of the damp petals.
The leaves were also based with the bright yellow color then allowed to dry.
The shading was applied with a grayed green (Olive Green) along the base and erratically up the center.
The veins were wiped back with a damp brush while the paint was still wet.
The center of the flower was created by rubbing two Styrofoam balls together to create little bits of foam.
I put these into a small snack zip lock bag and added a few drops of dark brown India ink on top of the bits.
Close the bag and smoosh the ink and foam together to color the foam.
It doesn't matter if it is evenly colored, as that will give a variation of color to the center.
Open the bag and allow the foam to dry.
When it is thoroughly dry, glue to the center of the flower.
You may have to build it up in layers to get good coverage. Once it had dried, I applied a wash of Black India ink to the center to darken that area.