The easier trick is to sew toggles and loops onto the far corners of the duvet and the inside of the duvet cover.

Turn the cover inside out.

Attach the duvet corners to their loops.

Pull the duvet cover inside out, over the duvet.

Fasten and shake.

Not only does this make putting the cover on easier (which I don't mind doing anyway) but it stops the duvet creeping around inside the cover so that there's a solid lump down the bottom while you're freezing up the top with only two thin sheets over yourself. Now that bit I really do hate.



I once had a cat that enjoyed nesting _inside_ the duvet cover. Always check before shaking the duvet out!