Duvet covers are quickly filtering to the top of my do not like list. It's like wrestling an octopus. The problem is that there is an opening on one side, and you have to fit the duvet into all the corners and have it be flat and even. Hmphf. I've looked at videos, and none seem to be very easy. I was pondering this the other night and a stroke of inspiration crossed my mind.
I'll start with flat sheets and sewing the bottom ends together. Then I'll put large plastic snaps on the remaining 3 sides. This is where all the work is, but once done, it doesn't have to be wrestled with. To insert the duvet, lay one half on the bed with the other half draped over the foot of the bed. Layer the duvet over that, then fold up the draped end over the duvet. Snap it up. I could even just put snaps all the way around so that when they are laundered, they will launder like separate sheets.
All the work is in adding the snaps, but once done, it makes the changing of the covers so much easier. Can you think of any reason why this wouldn't work?