Draw a small circle for the flower cluster center
Sketch many overlapping round petals around the center
Vary petal sizes and angles for a natural look
Add more small petal shapes to fill the cluster
Draw several clustered blooms to form the hydrangea head
Add a stem extending downward from the flower cluster
Sketch a few broad leaves along the stem
Draw leaf veins with simple curved lines
Refine the petal edges and cluster shape
Erase extra guidelines
Add shading to petals, leaves, and stem