I use this recipe to make seed balls:
7 parts clay powder, 5 parts sifted aged compost, 1 part fine grog (if available)
Mix compost and clay together dry, add in water gradually and work mixture until smooth, picking out any wood pieces from the compost.
Roll 1" ropes of the clay mix, pinch of 1" segments and lay them out. Indent them with your fingers to make a small bowl of each.
With clean and dry hands, portion out the seeds into the clay bowls.
Close bowls, roll in palms vigorously and carefully, rounding into a ball.