My friend Rommie showed me how to neatly stitch batting (being from Australia she called it wadding) to the foam and then how to make seamless seams in the wool fabric. My seams are not as seamless but I'm still very happy with them.
I had a learning curve with the foam. I bought 3" thick foam the first time but Winn noted that he didn't feel stable on that thickness. They couldn't trim the small pieces of foam so I bought a second set at 2" thick.
These cushions work great and our home is more comfortable for us and our guests.