For the first layer, I used a wool mattress pad that I had for a few years.  Next I used two layers of your wool batting and put the buckwheat hull pillow inserts I made on top of the wool batting.  I made the pillow inserts out of organic cotton twill.  Then I pulled the two layers of wool batting on top to cover the pillow inserts.  Finally I zipped it all up and was done!  It came out pretty well, I think.  I’m going to see what it’s like sleeping on it for a while and might decide to add more wool batting at some point.

UPDATE: After sleeping on it for a few nights, I ended up putting the buckwheat hull pillows on top of the layers of wool batting.  That seems to work better somehow.  I think it makes the buckwheat pillows a little more adjustable.  It’s very comfortable now although I still might add more layers of wool batting at some point. – L. G.