1. Turn the comforter cover inside out
2. Put your hands inside the comforter and grab hold of the back 2 corners and hang onto them (this means that if the cover was extended, you would be inside of it, but instead it's bunched up on your arms).
3. With your hands still inside the comforter cover, grab the 2 corners of the comforter so that each hand has a corner of the cover and a corner of the quilt.
4. Then shake the cover right side out over the comforter, holding on tight to the corners. This takes some perfecting as the cover will likely get caught about halfway down on the quilt. So go back and forth between the bottom and the top until it's all covered. Then button or zip and you're done. And exhausted.
In fact recently after a number of hotel stays we've been thinking about switching to the double flat sheet method whereby instead of a cover, you just have a flat sheet on the top and bottom of the quilt. It's more work to make the bed everyday but less work wrangling...