It seems complicated, sometimes it resembles a fight. However, it is easier than one might think and with the few steps shown here, it will be no problem! Lets get the duvet dressed then!
To begin lay your "naked" duvet on your bed in the way you will need it. To tell the right way (length and width) you can make reference to the Daunenstep label, which needs to be in the lower right corner.
Take the duvet cover and turn it inside out with the stitching outside (some prefer to iron the duvet inside out and to leave it like this to facilitate the "dressing" of the duvet). Put your hands in the cover and grab the corners firmly. At this point you will also have your arms inside the cover.
Without loosing the corners of the duvet cover grasp the corners of the duvet on the bed. In both hands you will now have the corners of the duvet cover and the duvet.
You almost got it! Bend yourself forward and allow the cover to slide over the duvet. Finish the operation by shaking the duvet. Keep duvet cover and duvet together in your hands and re-fluff properly.