Cut the fabric into the size and shape you want your pillow to be (allow 1/2 inch extra for seams). My fabric was about 20x24 inches.
Lay the two pieces of fabric on top of each other with the right sides facing each other and pin the edges together. The wrong side of the fabric will be on the top and bottom.
Sew three sides and half of the remaining side. Leave an opening to fill with the buckwheat hulls and herbs (if using).
Turn the pillow cover right side out and fill it with the buckwheat and herbs (if using).
Fold the unsewn fabric edges down into the opening and pin the edges together. The pinned area should lay flush with the already sewn area.
Hand sew or use your sewing machine to seal the opening.
Notes
Be sure to use a pillowcase to cover your buckwheat pillow and replace it after 2 years. I also like to lay mine in the sun every month to help disinfect.Instead of sewing the opening close, you could add a zipper if desired. This tutorial shows how.