Here are all the stencils that I've collected. The instructions shown below came with the hand-shaped henna stencils, which in turn came with the gift of supplies brought back from India. The stencils came as one green and one red of each pattern: bilaterally symmetrical versions of each design. They are a significant amount of size smaller than my hands, and I've got fairly small hands. I also got some round stencils of the same material and styles as the hands.
The two totally green stencils (middle row, center and right) are from a hair salon in Chicago's Little India that also does henna for wedding ceremonies. Their portfolio in the store was astoundingly beautiful.