Put cut sunflowers in a jar, place the jar in the center of a table and use the flat surface for drawing and painting the sunflowers.
Tape watercolor paper to the drawing board with acid-free masking tape. Then make a very light sketch with the 2H or 4H pencil. Take special note of the long yellow petals, the green bract-like sepals and the large dark brown composite head.
Wet the area of yellow petals with water and apply some yellow paint while the paper is still wet. Use yellow cadmium for the highlight and place the yellow ocher at the base of the corolla as a darker shade. It is okay if the colors run together. Use a pointed round.
Apply water to the dark center of the flower with a filbert brush. Next, add a highlight color (yellow ocher is a good choice) to the wet area, followed by a darker base color, like burnt umber or raw sierra. Botanists refer to the central portion of the sunflower as the head. If you look closely, you will see the head is filled with tiny individual flowers. Try to recreate the rough, dark texture created by all these tiny flowers when you paint the head.
Wet the leafy area and apply a combination of the two green colors, sap green or Hooker's green light. A touch of of raw ocher or raw sierra can be added for toning. Use a pointed round brush to complete this part of the picture.
Let the flower part of the painting dry and then wet the surrounding area and paint the background.