Alternatively, draw two circles, one inside the other, and fill the space between the two with simple pencil sketches of seed shapes. I’ve used acorns, pine cones, conkers, linden or lime seeds, sycamore or acer seeds and hawthorn berries. Place big items (like pine cones) in odd numbers, spaced relatively evenly around the circle. Fill in the spaces in between with leaves and then smaller seeds.